27 February 2014 Developments of mid-infrared optical parametric oscillators for spectroscopic sensing: a review
Author Affiliations +
Optical parametric oscillator is an attractive way of generating tunable mid-infrared light in the spectral range where lasers simply do not exist—for the needs of spectroscopy, medical applications, remote sensing, etc. We will go through the fundamentals of the optical parametric oscillator first and then introduce the related new phase-matching, cavity design, and spectroscopic techniques.



An optical parametric oscillator (OPO) is a coherent light source similar to a laser, but based on the optical parametric amplification in a nonlinear crystal rather than the stimulated emission in a gain media. It was first achieved in 1965 by Giordmaine and Miller,1 but theoretical works were even earlier.2,3 A main attraction of OPOs is to generate widely tunable coherent radiation [e.g., in the mid-infrared (mid-IR), far-infrared, or terahertz spectral region), which are difficult or impossible to obtain from any laser. This makes OPOs very valuable for laser spectroscopy and its applications in sensing.4

The vibrational spectrum of a molecule is considered to be a unique physical property and is characteristic of the molecule even in a complexed environment.5 For the specific mid-IR spectral region of 2 to 20 μm (500 to 5000cm1), it is of great interest. A large number of molecules undergo strong characteristic vibrational transitions in this spectral region (Fig. 1). Mid-IR spectroscopy provides a powerful tool not only for understanding the structure of a molecule and its governing physical laws, but also for performing nonintrusive diagnostics of composite systems of physical, chemical, or biological interests, including isotopologues, in the gas, liquid, or solid phase.6,7

Fig. 1

HITRAN simulation of absorption bands of various molecules in the 500 to 5000cm1 spectral region.8


Furthermore, there are two important windows (3 to 5 μm and 8 to 13 μm) in the Earth’s atmosphere that is relatively transparent. These regions can be exploited to detect small traces of environmental and toxic vapors down to the sensitivities of parts-per-billion (ppb) in a variety of atmospheric, astronomic, geophysical, security, and industrial applications. The low Rayleigh scattering losses in the mid-IR spectral region (λ4) benefit tomography and imaging in turbid media.7,9

Within the last decade, the development of the optical frequency comb has allowed frequency and time measurements with previously unattainable precision, facilitated carrier-envelope phase stabilized lasers, and revolutionized the field of spectroscopy.1011.12 A mode-locked femtosecond laser gives a regular comb spectrum of millions of laser modes with a spacing equals to the pulse repetition frequency. Optical frequency combs in the visible and near-IR domains have enabled the development of new ultraprecise optical atomic clocks, and commercially available combs have become standard instruments of precision spectroscopy. They are now becoming enabling tools for many applications, ranging from the calibration of astronomical spectrograph to molecular spectroscopy. In the mid-IR range, the advent of femtosecond optical combs is expected not only to bring a new set of tools for precision spectroscopy, but also to allow spectroscopy to be explored in a broader sense. Precise investigations of changes in the composition of a molecular sample over a large dynamic range might also soon be within reach thanks to novel mid-IR frequency-comb-based techniques.

Mid-IR OPO shows great potentials in spectroscopy-related applications in sensing. Over the last few years, many research groups all over the world have done tremendous great works on this research. In this review, we will go through the fundamentals of the OPO first and then introduce some of those novel developments.


Fundamentals of OPO

Optical parametric amplification/oscillation belongs to a broader class of electromagnetic phenomena described within the framework of the general Maxwell equations. With the assumption of the absence of extraneous charges and currents, we can write the set of Maxwell equations in the form









The relationship between the electric flux density D and the electric field E depends on the electric properties of the medium, which are characterized by the polarization density P.



We take the curl of the curl-E Maxwell equation [Eq. (3)] and interchange the order of space and time derivatives on the right-hand side of the resulting equation. With knowing that ××E=(·E)2E, we obtain



It is often convenient to split P into a linear and a nonlinear part (with subscripts of L and NL, respectively): P=PL+PNL. By introducing ϵ1, a complex frequency-dependent dielectric tensor, we can rewrite Eq. (6) as



When PNL=0, Eq. (7) describes the light propagating in a dissipative medium but without any cross-talking of different frequency components of the light. However, if PNL0, we start to see more interesting nonlinear effects. For a more rigid derivation of Eq. (7), readers can find details in Refs. 1314. to 15, and here we concentrate on the OPO only.

In a typical OPO, a shorter-wavelength laser pumps the second-order nonlinear susceptibility of a suitable optical material, introducing of PNL, to generate lower-frequency components. Combined with an appropriate resonator for optical feedback, oscillation can be established at one or more wavelengths, called single or multiple resonant OPO (see Sec. 4). The oscillation wavelength is often tuned by adjusting the parameters of the resonator or the nonlinear material, e.g., the orientation and temperature of the nonlinear material.

Let us now consider the situation shown in Fig. 2, in which optical waves at frequencies ωp and ωs interact in a lossless nonlinear optical medium and produce an output wave at the difference frequency ωi=ωpωs, where ω is frequency; in this whole paper, subscripts p, s, and i stand for pump, signal, and idler, respectively. For a fixed polarization and propagation geometry, it is possible to express the nonlinear polarization for OPO/OPA system as a scalar relationship PNL(ωp)=4ϵ0deffE(ωi)E(ωs) (deff is the effective nonlinearity). If the applied fields are linear polarized and propagate along z direction, we can represent the applied fields as


Fig. 2

A typical optical parametric oscillator: pump laser ωp pumps the nonlinear crystal deff. The signal beam ωs is resonant, whereas the idler ωi is ejected by the resonator mirrors. However, cavity can also be designed to resonant with pump laser and idler beam too (Sec. 4).


Here, we already take into account the cases when the applied fields are pulses (A is the envelope amplitude of the field). At the same time, we can approximate the wave vector as a Taylor expansion: k=k0+k(ωω0)+1/2k(ω0ω)2, k=dk/dω=1/vg, where vg is the group velocity and k is the group velocity dispersion. As we all know, the requirement for such expansion is the quantity |ω0ω|ω0. However, it is still valid for broad bandwidth femtosecond pulses in many cases.16 By applying slowly varying envelope approximation (|d2A/dz2||kdA/dz|), we can obtain the coupled-wave equations for OPA as







It is easy to see there is an oscillating term of e±i(ks+kikp)z, which gives the phase-matching condition. When the phase-matching condition is fulfilled Δk=ks+kikp=0, the individual atomic dipoles that constitute the material system are properly phased so that the field emitted by each dipole adds coherently in the propagation direction. The total power radiated by the ensemble of atomic dipoles thus scales as the square of the number of atoms that participate, and the signal and idler extract energy most efficiently from the pump laser.14 As the requirement of ωp=ωi+ωs is regarded as the energy conservation, the requirement of phase-matching can be viewed as the momentum conservation.

The coupling equations can be solved analytically with various initial conditions.17 For simplicity and practicality, we can neglect pump field depletion (dAp/dz=0) and assume the presence of no idler in the beginning of parametric process Ai(z=0)=0. The single-pass fractional gain in signal intensity (I=(1/2)ϵ0nc|A|2) is18,19


where l is the length of the nonlinear medium, Γ is the parametric gain factor given by


and g is the total gain factor given by



The parametric gain depends on the intensity of the pump laser, as well as on the material, e.g., nonlinear coefficient, refractive index, and the interaction length. However, the phase-matching condition plays a very important role if not the most.20


Phase-Matching at Mid-IR

Due to the dispersion, the pump, signal, and idler have different phase velocities. The relative phase of the interactive waves varies along the medium. A measure of the phase mismatch is the coherence length Lc=|π/Δk|, which defines the distance over which the relative phase of the interacting waves shifts by π. The propagation beyond the coherence length, which is typically several micrometers, leads to the energy back-conversion from the generated waves into the pump wave.20

However, the phase-matching can be achieved by making use of the birefringence: choosing the orientation of the crystal so that the pump laser (highest frequency) propagates along the fast axis (smaller refraction index) and the signal and idler propagate along the slow axis (larger refraction index).21 The process is called type I phase-matching when both signal and idler have the same polarization perpendicular to that of the pump laser. For type II phase-matching, the polarization of the signal and idler are perpendicular to each other.14,20,22,23 In most literatures, the phase-matching is explained by using the uniaxial crystal and giving a series of combinations. Those combinations are meaningless for biaxial crystals, but the principle is same. This phase-matching achieved by tuning crystal angles is sometimes called critical phase-matching. The attribute critical comes from the fact that this technique is relatively sensitive to the misalignment of the three beams.22 A consequence of critical phase-matching is the spatial walk-off generated by the birefringence, which reduces the interaction length of the optical waves. It can be compensated via a noncollinear geometry.2324.25 A major advantage of critical phase matching is that the crystal temperature can often be close to room temperature, so that a crystal oven is not required.

On the other hand, this birefringence can be fulfilled by changing the temperature of the nonlinear crystal: noncritical phase-matching.26,27 Noncritical phase-matching is sometimes called temperature phase-matching or 90 deg phase-matching. The interacting beams are aligned such that they propagate along same axis of the birefringent nonlinear crystal. The phase-matching is achieved by adjusting the crystal temperature such that the phase velocities of the interacting waves are equal (polarizations are adjustable parameters, too). It results in the absence of spatial walk-off and less angular sensitivity, which is important in applications with tight focusing. As shown in Eq. (11), the gain is proportional to the intensity; therefore, the conversion efficiency can often be higher with noncritical phase-matching because of the tight focusing. At the same time, the crystal temperature is usually somewhat above room temperature, so that a temperature-stabilized crystal oven is required, which protects those crystals from being deliquescence.

Many nonlinear crystals are frequently used for mid-IR OPO,23 and some of them are listed in Table 1.

Table 1

Frequently used nonlinear crystals for mid-IR optical parametric oscillators.

CrystalSpectral regions (μm)References
Lithium niobate (LiNbO3)0.35 to 5.227, 28
Potassium titanyl phosphate (KTP)0.35 to 4.529 to 31
KTiOAsO4 (KTA)0.35 to 5.532 to 34
β-barium borate (BBO)0.19 to 3.335
Lithium triborate (LBO)0.16 to 2.636
Zinc germanium diphosphide (ZGP)0.7 to 1237, 38
Silver gallium sulfide and selenide (AgGaS2 and AgGaSe2)0.5 to 13.2/0.78 to 1839, 40
Cadmium selenide (CdSe)0.75 to 2541
LiGaS2, LiGaSe2, and LiGaTe20.33 to 12/0.38 to 14/0.52 to 1542

However, there are limits to utilize the birefringence of an optical material to achieve the phase-matching. First, not all nonlinear materials may possess birefringence (e.g., isotropic semiconductors zinc selenide and gallium arsenide), or may possess sufficient birefringence to compensate for the dispersion of the linear refractive index over the wavelength range of interest. Second, sometimes nonlinearity is low or 0 under the phase-matching condition (deff varies with the orientation of a crystal). These difficulties led researchers to find a way to achieve phase-matching by periodically altering the sign of the nonlinear coefficient, so-called quasi-phase-matching (QPM).43,44 The relative phase between the three waves is corrected using a periodic change in the sign of the nonlinear susceptibility before the back-conversion starts.14


where Λ is the period of the alternation of the crystalline. This spatial modulation causes a phase mismatching ΔkQ=ks+kikp2π/Λ.14,44 The optimized phase-matching condition can be achieved if



Although the technique of QPM (Fresnel QPM) was proposed in 1962 (Ref. 43) and demonstrated in 1965,45 difficulties in fabrication of the periodic structure in the range of the coherence length (typically 1 to 100 μm) have prevented its realization. The relative phase shift experienced at total internal reflection is used to reset the relative phases between interacting waves.4647.48

The advances in the fabrication of structured ferroelectrics, meanwhile, have established this technique for efficient frequency-conversion applications.49,50

QPM offers two major advantages over birefringence phase-matching. First, the polarization of the interacting waves can be same. This allows the use of the largest deff coefficient of the crystal, which reduces the pump threshold and increases the conversion efficiency.14,20 The second advantage is that the QPM of any combination of pump, signal, and idler wavelength can be realized in such materials. In addition, QPM provides design flexibility of nonlinear conversion devices by engineered domain structures.20 The most challenging aspect of the fabrication is the periodic nonlinear structure. This may be accomplished by lithographically exposing the crystal to a periodic electric field that reverses the direction of the crystal’s permanent electric polarization, a technique called poling. This approach has been applied to ferroelectric crystals, such as LiTaO3, potassium titanyl phosphate, and LiNbO3; the latter has spawned a technology known as periodically poled lithium niobate.51 Nowadays, people can have highly efficient OPO operate at continuous-wave (CW) with low threshold.52

The zincblende semiconductors, such as GaAs, ZnSe, and GaP, have large nonlinear susceptibilities and low optical absorption into the mid-IR spectral region. They have long been used for mid-IR nonlinear optics. As pointed out above, their optical isotropy, a consequence of their cubic crystal structure, precludes birefringent phase-matching.53 The QPM really gives an opportunity to apply these high-nonlinearity crystals in mid-IR spectral region.

A number of QPM techniques based on stacks of crystal plates with alternating orientation have been explored, but fabrication has proved to be challenging.5354.55.56.57 The best way to fabricate stacked-plate is to have crystal plates being diffusion-bonded to each other. Diffusion bonding consists of carefully polishing, cleaning, and placing. To avoid the localized scattering losses and a constant Λ, it requires very high fabricating performance.

The difficulty in fabricating suitable stacks of plates for QPM suggests that a monolithic structure would be more applicable. Epitaxial growth of orientation-patterned materials, with lithographically controlled patterns, has greatly opened the range of applicability of QPM.53,58 In template controlled growth, a substrate is patterned lithographically such that the orientation of subsequently grown films is controlled by the pattern on the substrate. Multilayer, thin-film growth on such a template, for example, by molecular-beam epitaxy or organometallic vapor-phase epitaxy, can produce a QPM waveguide device, while thick-film growth on the template, for example, by hydride vapor-phase epitaxy, can produce a bulk (millimeter-thick) film for QPM interactions.53

Now, people obtained high efficiency OPO with an orientation-patterned (OP) GaAs with tuning range covering from 2 to 9 μm.59,60 A major constraint of OPGaAs-based OPO is the strong two-photon absorption, which limits the pump of OPGaAs with wavelengths longer than 1.8μm.61 Lasers operating at this wavelength (2 μm), like the Tm,Ho:YLF laser, are preferable for their relative simplicity.6263.64 With such femtosecond thulium fiber laser as pump source, broadband mid-IR OPO can be achieved. Output bandwidth covers from 2.6 to 6.1 μm at the 30 dB level65 and can be applied to the carrier-envelope offset (CEO) frequency measurements. In one such measurement, the authors show that the CEO frequency of the synchronously pumped OPO signal wave is a linear function of the CEO frequency of the pump laser, with a slope determined by the signal to pump center-frequency ratio.66

Other than the phase-matching techniques mentioned above, very recently people found the random motion of the relative phases in highly transparent polycrystalline materials can be an effective strategy for achieving efficient phase-matching in isotropic materials.67 The back-conversion of signal and idler to pump is a result of an interference effect between the three coherent lights. Such interference could be destroyed if the waves were allowed to lose their respective phases randomly in the material, in that the nonlinear susceptibility does not average to zero. Because of the random phase, it leads to a coherent growth of the nonlinear generated fields according to N, where N is the number of the microcrystallite.67 Both the theoretical work and the experimental work show that the second-order nonlinear generation of light is also possible in structures of randomly oriented nonlinear domains,68 which could be useful for the OPA process in the future.


Architecture of OPO

As discussed in Sec. 1, OPO operates like a laser. It requires the same three elements of a laser: pump source, cavity, and gain media. Output of the OPO ranges from CW to femtosecond pulses. The design and performance of OPOs have a huge variety. The design of the cavity is strongly connected to the output characteristic of the pump source and the phase-matching condition. Three types of resonators are distinguished depending on the number of resonating waves.20,22

The singly resonant OPO (SRO) has highly reflecting mirrors at either the signal or the idler light, and dichroic resonator mirrors or some polarizing optics are used to make high resonator losses for the nonresonant lights, so that there is very little optical feedback. In principle, this configuration is of particular importance in providing continuous wavelength tunability since it gives less restriction on the cavity. It also has a high stability and a narrow linewidth output.69,70 However, the disadvantage of the SRO is the losses of the other lights. From the coupling equation discussed above, we can see that the SRO will require higher pump power and has higher oscillation threshold. With the help of high quality of optics, novel cavity configurations, and crystals, people have made highly efficient CW mid-IR OPOs, and the threshold has been reduced from a couple watts to several hundred milliwatts.7172.73.74.75

For doubly resonant OPO (DRO) configurations where both signal and idler waves are resonated, the threshold could be reduced by one to three orders of magnitude.20 As the DRO is overconstrained by the requirements of energy conservation, phase-matching, and simultaneous resonance of signal and idler waves, perturbations on the pump frequency or OPO cavity length can cause large power fluctuations and mode hopping of the DRO.20,76 However, these problems can be overcome by using frequency-stable, single-mode lasers.77,78 The doubly resonant configuration where pump and signal (or idler) are resonated is called pump-enhanced SRO and provides a compromise between the low threshold of DROs and the wide tunability of SROs.20,79

Triply resonant OPOs suffer from the combined problems of both types of DROs with smaller tunability in comparison to SRO, but they offer lowest threshold (can be seen from the coupling equations) in the range of several milliwatts or less.20,80,81

For the new developments of OPOs at CW, nanosecond, and femtosecond different pulse durations, readers can find more details in Refs. 82 and 83.

All the OPOs talked above rely on nonlinear crystals placed into external cavities and pumped by powerful external lasers. They tend to be relatively complex and large devices that are difficult to align and miniaturize, so great efforts have been devoted to develop integrated devices. Recently, researchers reported a monolithic semiconductor triple microcavity OPO with signal, pump, and idler waves propagating along the vertical direction of the nanostructure. The pump threshold is low enough to envisage the realization of an all-semiconductor electrically pumped microparametric oscillator.84 There are efforts being made to combine an OPO with a microcavity to generate mid-IR frequency combs too.85

Another idea is to make use of backpropagation wave to achieve effective OPO, which was first proposed in 1966.86 In that initial study, birefringence in the nonlinear crystal was used, and it was only applicable to the case where the idler frequency was in the far-IR region. In 2007, the first experiment of mirrorless OPO was conducted, and it was fullfiled via QPM.87 This counterpropagating parametric interaction, where the signal and idler waves propagate in opposite directions, puts much stronger constraints on the momentum mismatch, thus promising much better control over the spectrum. These unique properties open up possibilities for broadband pulse generation in the near-IR or mid-IR regions, and for tuning a narrow band mid-IR idler wave with high precision.87,88


Sensing Applications of Mid-IR OPO

As mentioned in the Introduction, mid-IR OPO is an important coherent light source for molecular spectroscopy and it provides sensitivity and selectivity.

The fact that molecules absorb light at distinct, characteristic wavelengths allows for the unique spectral identification of a chemical by measuring its absorption spectrum. With the development of OPOs, it has become increasingly important to use OPO as a tunable coherent light source to monitor and detect trace gases in diverse fields ranging from pollution and greenhouse-gas emission, to applications involving environmental control for the workplace and space habitats.4,89,90 Trace gas detection using a CW tunable SRO was reported to have an ethane detection sensitivity <1ppb, which was close to the best values achieved with conventional method.91 Compact OPO system was also used for remote sensing explosives vapor detection at ppb level.92

Other than conventional absorption spectroscopy, there are many new spectroscopic technologies developed, especially the frequency combs technique.10,12 Mid-IR OPO shows great advantages in a new very sensitive absorption spectroscopy technique, called cavity-ring-down spectroscopy. Instead of measuring the small difference between the incident and transmitted radiation power in conventional absorption spectroscopy, this technique measures the number of cavity round-trip times after which the power has dropped to 1/e of its initial value.20,9394.95

The direct frequency comb spectroscopy directly employs optical frequency combs to probe spectral features in a massively parallel probing in the frequency domain with a comb bandwidth spanning tens to hundreds of terahertz.96 It also allows time-resolved studies of coherent and incoherent dynamics. Femtosecond OPO provides high-power frequency combs in the mid-IR spectral region and fits very well for these applications.97,98 These OPOs can operate both for broad band width and widely tunable applications.99,100

Cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) emerged as a powerful new technique that provides high spectral coverage, high resolution, and high sensitivity by combining the frequency comb with several other important elements, including an external enhancement cavity and a broadband, yet highly resolving, detection system.101102.103 This enhanced spectroscopy technique can be applied to breath analysis, a medical diagnostics demonstrating that some molecules in the breath are potential markers for certain diseases.104 Using intracavity spectroscopy of broadband OPO, researchers achieved ultrasensitive detection of methane, isotopic carbon dioxide, carbon monoxide, formaldehyde, acetylene, and ethylene as well.105

Thanks to the precision spectroscopy, spectral shifts of transition frequencies associated with different isotopes can be detected. The determination of isotope ratios has proved to be a powerful tool in medical analysis, geology, and climate research. Stable isotopes of H2O, CO2, and O2 are analyzed in ice cores to track the history of the Earth’s climate. They are also used for atmospheric studies and to observe groundwater transport. A precise measurement conducted with mid-IR OPO of the ratio of the two stable carbon isotopes of CO2 (CO213and CO212) can provide valuable information about CO2 exchange processes in the volcanic plume.106,107

The invention of the femtosecond frequency comb really made revolutions in the field of spectroscopy. Besides the newly developed techniques discussed above, dual frequency comb spectroscopy (DFCS) emerges as a promising, highly sensitive, and superior fast spectroscopy with high resolution to complement the traditional Fourier transform spectroscopy (FTS). In dual-comb spectroscopy, two frequency combs with slightly different line spacings are heterodyned after passing through the cell, yielding a downconverted radio frequency comb that contains information on the absorption experienced by both combs.7,108,109 Compared to traditional FTS, DFCS is extremely fast. A fast oscilloscope can display an interferogram and the broadband spectrum by fast Fourier transform in real time. The signal record then can be transformed to a spectrum with high resolution at high signal-to-noise ratio, and part-per-billion detection limits was achieved for several important molecules, including methane, ethane, isoprene, and nitrous oxide.110,111 Instead of using two frequency-locked OPOs as the dual-comb source, a dual-comb source is comprised of a single synchronously pumped OPO driven by two independent lasers and capable of producing two mid-IR pulses sequences.112

The combination of frequency combs with a Fabry-Perot filtering cavity is a promising approach to achieve high Doppler shift resolution via the spectrograph wavelength calibration. This high resolution can be used to search for extrasolar planets and to observe in real time the evolution of the cosmological redshift of distant objects, called as astro-comb technique, and OPO offers the freedom of both important parameters: the optical frequency and the repetition rate.113114.115

Based on the frequency combs, a coherent anti-Stokes Raman spectroscopy system was developed to perform spectroscopic imaging over a broad spectral bandwidth within a few microseconds.116 OPOs are perfect tools to generate suitable frequency combs for various spectral regions and further to extend its applications.



A novel technique is achieved to generate mode-locked pulses from a CW OPO.117 This technique is based on the deployment of an amplitude/phase modulator in combination with a CW OPO, simultaneously providing spectral broadening and nonlinear parametric gain.117,118 This approach could enable the generation of tunable ultrashort pulses in the mid-IR spectral regions using OPOs directly pumped by CW lasers.

Another new frequency comb generation principle has emerged that uses parametric frequency conversion in high resonance quality factor microresonators. This approach provides access to generate high repetition rate frequency combs through compact system, chip-scale integration, and benifit a number of comb applications, such as in astronomy, microwave photonics, or telecommunications.85,119

Mid-IR OPOs also have great potential in biomedical applications. Not only their tunable wavelength systems can be used for the imaging of bio-samples, but also their ablation capability can be used for clinic surgical applications.120,121

Thanks to the new nonlinear crystals, improved optics components, and new spectroscopy techniques, the applications of OPOs have been significantly extended in the last 10 years. We would expect that the sensing related application will be further improved in the future, especially with the trace gas detection and biomedical-related imaging process. With the boosts of these applications, the size of OPOs will be further reduced and the performance of them will be further improved as well.


The author acknowledges Dr. F. Zhu who provided the script for plotting Fig. 1.


1. J. A. GiordmaineR. C. Miller, “Tunable coherent parametric oscillation in LiNbO3 at optical frequencies,” Phys. Rev. Lett. 14(24), 973–96 (1965).PRLTAO0031-9007 http://dx.doi.org/10.1103/PhysRevLett.14.973 Google Scholar

2. R. H. Kingston, “Parametric amplification and oscillation at optical frequencies,” Proc. IRE 50, 472–474 (1962).PIREAE0096-8390 Google Scholar

3. A. E. Siegman, “Nonlinear optical effects: an optical power limiter,” Appl. Opt. 1(S1), 127–132 (1962).APOPAI0003-6935 http://dx.doi.org/10.1364/AO.1.000127 Google Scholar

4. F. K. TittelD. RichterA. Fried, “Mid-infrared laser applications in spectroscopy,” in Solid-State Mid-Infrared Laser Sources, I. T. SorokinaK. L. Vodopyanov, Eds., pp. 458–529, Springer, Berlin, Heidelberg (2003). Google Scholar

5. A. V. Sokolov, “Applications of coherent Raman scattering,” in Extreme Photonics & Applications, T. J. HallS. V. GaponenkoS. A. Paredes, Eds., pp. 75–93, Springer, Netherlands (2010). Google Scholar

6. J. P. Coates, “A practical approach to the interpretation of infrared spectra,” in Encyclopedia of Analytical Chemistry, R. A. Meyers, Ed., pp. 10815–10837, J. Wiley & Sons Ltd., Chichester, United Kingdom (2000). Google Scholar

7. A. SchliesserN. PicqueT. W. Hansch, “Mid-infrared frequency combs,” Nat. Photonics 6(7), 440–449 (2012).1749-4885 http://dx.doi.org/10.1038/nphoton.2012.142 Google Scholar

8. L.S. Rothmanet al., “HITEMP, the high-temperature molecular spectroscopic database,” J. Quant. Spectrosc. Radiat. Transf. 111, 2139–2150 (2010).JQSRAE0022-4073 http://dx.doi.org/10.1016/j.jqsrt.2010.05.001 Google Scholar

9. E. H. Wishnowet al., “Mid-infrared interferometry with high spectral resolution,” Proc. SPIE 7734, 773409 (2010).PSISDG0277-786X http://dx.doi.org/10.1117/12.857656 Google Scholar

10. Th. UdemR. HolzwarthT. W. Hansch, “Optical frequency metrology,” Nature 416(6877), 233–237 (2002).NATUAS0028-0836 http://dx.doi.org/10.1038/416233a Google Scholar

11. S. T. CundiffJ. Ye, “Colloquium: femtosecond optical frequency combs,” Rev. Mod. Phys. 75(1), 325–342 (2003).RMPHAT0034-6861 http://dx.doi.org/10.1103/RevModPhys.75.325 Google Scholar

12. D. J. Joneset al., “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288(5466), 635–639 (2000).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.288.5466.635 Google Scholar

13. Y. R. Shen, The Principles of Nonlinear Optics, Wiley, New York (1984). Google Scholar

14. R. W. Boyd, Nonlinear Optics, Academic Press, San Diego (2003). Google Scholar

15. A. NewellJ. Moloney, Nonlinear Optics, Westview Press, Boulder, Colorado (2003). Google Scholar

16. T. BrabecF. Krausz, “Nonlinear optical pulse propagation in the single-cycle regime,” Phys. Rev. Lett. 78(17), 3282–3285 (1997).PRLTAO0031-9007 http://dx.doi.org/10.1103/PhysRevLett.78.3282 Google Scholar

17. J. A. Armstronget al., “Interactions between light waves in a nonlinear dielectric,” Phy. Rev. 127(6), 1918–1939 (1962).PHRVAO0031-899X http://dx.doi.org/10.1103/PhysRev.127.1918 Google Scholar

18. E. Harris, “Tunable optical parametric oscillators,” Proc. IEEE 57(12), 2096–2113 (1969).IEEPAD0018-9219 http://dx.doi.org/10.1109/PROC.1969.7495 Google Scholar

19. R. L. Byer, “Optical parametric oscillators,” in Quantum Electronics, Nonlinear Optics, H. RabinC. L. Tang, Eds., Vol. 1, pp. 587–701, Academic, New York (1975). Google Scholar

20. F. Träger, Handbook of Laser and Optics, Springer, New York (2007). Google Scholar

21. P. D. Makeret al., “Effects of dispersion and focusing on the production of optical harmonics,” Phys. Rev. Lett. 8(1), 21 (1962).PRLTAO0031-9007 http://dx.doi.org/10.1103/PhysRevLett.8.21 Google Scholar

22. R. Paschotta, Encyclopedia of Laser Physics and Technology, Wiley-VCH (2008). Google Scholar

23. G. DmitrievG. G. GurzadyanD. N. Nikogosyan, Handbook of Nonlinear Optical Crystals, Springer, Berlin, Heidelberg (1991). Google Scholar

24. P. Di Trapaniet al., “Matching of group velocities in three-wave parametric interaction with femtosecond pulses and application to traveling-wave generators,” J. Opt. Soc. Am. B 12(11), 2237–2244 (1995).JOBPDE0740-3224 http://dx.doi.org/10.1364/JOSAB.12.002237 Google Scholar

25. K. Moutzouriset al., “Efficient second-harmonic generation in birefringently phase-matched GaAs/Al2O3 waveguides,” Opt. Lett. 26(22), 1785–1787 (2001).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.26.001785 Google Scholar

26. D. H. Jundt, “Temperature-dependent Sellmeier equation for the index of refraction, ne, in congruent lithium niobate,” Opt. Lett. 22(20), 1553–1555 (1997).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.22.001553 Google Scholar

27. A. Bruneret al., “Temperature-dependent Sellmeier equation for the refractive index of stoichiometric lithium tantalate,” Opt. Lett. 28(3), 194–196 (2003).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.28.000194 Google Scholar

28. M. D. EwbankM. J. RoskerG. L. Bennett, “Frequency tuning a mid-infrared optical parametric oscillator by the electro-optic effect,” J. Opt. Soc. Am. B 14(3), 666–671 (1997).JOBPDE0740-3224 http://dx.doi.org/10.1364/JOSAB.14.000666 Google Scholar

29. K. Kato, “Parametric oscillation at 3.2 μm in KTP pumped at 1.064 μm,” IEEE J. Quantum Electron. 27(5), 1137–1139 (1991).IEJQA70018-9197 http://dx.doi.org/10.1109/3.83367 Google Scholar

30. Q. FuG. MakH. M. van Driel, “High-power, 62-fs infrared optical parametric oscillator synchronously pumped by a 76-MHz Ti:sapphire laser,” Opt. Lett. 17(14), 1006–1008 (1992).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.17.001006 Google Scholar

31. W. S. PelouchP. E. PowersC. L. Tang, “Ti:sapphire-pumped, high-repetition-rate femtosecond optical parametric oscillator,” Opt. Lett. 17(15), 1070–1072 (1992).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.17.001070 Google Scholar

32. K. Zhonget al., “High-pulse-energy high-efficiency mid-infrared generation based on KTA optical parametric oscillator,” Appl. Phys. B 100(4), 749–753 (2010).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-010-3932-y Google Scholar

33. R. F. Wuet al., “Multiwatt mid-IR output from a Nd:YALO laser pumped intracavity KTA OPO,” Opt. Express 8(13), 694–698 (2001).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.8.000694 Google Scholar

34. F. Baiet al., “Theoretical and experimental studies on output characteristics of an intracavity KTA OPO,” Opt. Express 20(2), 807–815 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.000807 Google Scholar

35. J. Y. Zhanget al., “Optical parametric generation and amplification in barium borate and lithium triborate crystals,” J. Opt. Soc. Am. B 10(9), 1758–1764 (1993).JOBPDE0740-3224 http://dx.doi.org/10.1364/JOSAB.10.001758 Google Scholar

36. J. Honget al., “Broadly tunable femtosecond pulse generation in the near and mid-infrared,” Appl. Opt. 36(9), 1894–1897 (1997).APOPAI0003-6935 http://dx.doi.org/10.1364/AO.36.001894 Google Scholar

37. A. Hemminget al., “99 W mid-IR operation of a ZGP OPO at 25% duty cycle,” Opt. Express 21(8), 10062–10069 (2013).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.21.010062 Google Scholar

38. Ab. F. Nieuwenhuiset al., “Mid-infrared ZGP optical parametric oscillator directly pumped by a lamp-pumped, Q-switched Cr,Tm,Ho:YAG laser,” Proc. SPIE 6455, 645518 (2007).PSISDG0277-786X http://dx.doi.org/10.1117/12.700618 Google Scholar

39. K. L. Vodopyanovet al., “AgGaS2 optical parametric oscillator continuously tunable from 3.9 to 11.3 μm,” Appl. Phys. Lett. 75(9), 1204–1206 (1999).APPLAB0003-6951 http://dx.doi.org/10.1063/1.124642 Google Scholar

40. S. Chandraet al., “Continuously tunable, 6–14 μm silver-gallium selenide optical parametric oscillator pumped at 1.57 μm,” Appl. Phys. Lett. 71(5), 584–586 (1997).APPLAB0003-6951 http://dx.doi.org/10.1063/1.119920 Google Scholar

41. R. G. WenzelG. P. Arnold, “Parametric oscillator: HF oscillator-amplifier pumped CdSe parametric oscillator tunable from 14.1 μm to 16.4 μm,” Appl. Opt. 15(5), 1322–1326 (1976).APOPAI0003-6935 http://dx.doi.org/10.1364/AO.15.001322 Google Scholar

42. E. Pelletieret al., “Mid-infrared optical parametric amplifier based on a LGSe crystal and pumped at 1.6 μm,” Opt. Express 20(25), 27456–27464 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.027456 Google Scholar

43. J. A. Armstronget al., “Interactions between light waves in a nonlinear dielectric,” Phys. Rev. 127(6), 1918–1939 (1962).PHRVAO0031-899X http://dx.doi.org/10.1103/PhysRev.127.1918 Google Scholar

44. R. L. Byer, “Quasi-phasematched nonlinear interactions and devices,” J. Nonlinear Opt. Phys. Mater. 6(4), 549–592 (1997).JNOMFV0218-8635 http://dx.doi.org/10.1142/S021886359700040X Google Scholar

45. G. D. BoydC. K. N. Patel, “Enhancement of optical second-harmonic generation (SHG) by reflection phase matching in ZnS and GaAs,” Appl. Phys. Lett. 8(12), 313–315 (1966).APPLAB0003-6951 http://dx.doi.org/10.1063/1.1754454 Google Scholar

46. H. Komineet al., “Quasi-phasematched second-harmonic generation by use of a total-internal-reflection phase shift in gallium arsenide and zinc selenide plates,” Opt. Lett. 23(9), 661–663 (1998).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.23.000661 Google Scholar

47. R. Haidaret al., “Quasiphase-matched difference frequency generation (8–13 μm) in an isotropic semiconductor using total reflection,” Appl. Phys. Lett. 82(8), 1167–1169 (2003).APPLAB0003-6951 http://dx.doi.org/10.1063/1.1557326 Google Scholar

48. R. HaidarP. KupecekE. Rosencher, “Nonresonant quasi-phase matching in GaAs plates by Fresnel birefringence,” Appl. Phys. Lett. 83(8), 1506–1508 (2003).APPLAB0003-6951 http://dx.doi.org/10.1063/1.1604474 Google Scholar

49. D. Fenget al., “Enhancement of second harmonic generation in LiNbo3 crystals with periodic laminar ferroelectric domains,” Appl. Phys. Lett. 37(7), 607–609 (1980).APPLAB0003-6951 http://dx.doi.org/10.1063/1.92035 Google Scholar

50. S. ZhuY. Y. ZhuN. B. Ming, “Quasi-phase-matched third-harmonic generation in a quasiperiodic optical superlattice,” Science 278(5339), 843–846 (1997).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.278.5339.843 Google Scholar

51. B. E. A. SalehM. C. Teich, Fundamentals of Photonics, 2nd ed., Wiley, New York (2007). Google Scholar

52. A. HendersonR. Stafford, “Low threshold, singly-resonant CW OPO pumped by an all-fiber pump source,” Opt. Express 14(2), 767–772 (2006).OPEXFF1094-4087 http://dx.doi.org/10.1364/OPEX.14.000767 Google Scholar

53. P. S. KuoM. M. Fejer, “Microstructured semiconductors for mid-infrared nonlinear optics,” in Mid-Infrared Coherent Sources and Applications, M. Ebrahim-ZadehI. T. Sorokina, Eds., pp. 149–168, Springer, Dordrecht, The Netherlands (2008). Google Scholar

54. P. S. Kuo, “Thick film, orientation-patterned gallium arsenide for nonlinear optical frequency conversion,” PhD Dissertation, Stanford University (2008). Google Scholar

55. D. Zhenget al., “Diffusion bonding of GaAs wafers for nonlinear optics applications.” J. Electrochem. Soc. 144(4), 1439–1441 (1997).JESOAN0013-4651 Google Scholar

56. B. J. Perrettet al., “Optical parametric amplification of mid-infrared radiation using multi-layer glass-bonded QPM GaAs crystals,” Proc. SPIE 6455, 64550A (2007).PSISDG0277-786X http://dx.doi.org/10.1117/12.698942 Google Scholar

57. K. C. RustagiS. C. MehendaleS. Meenakshi, “Optical frequency conversion in quasi-phase-matched states of nonlinear crystals,” IEEE J. Quantum Electron. 18(6), 1029–1041 (1982).IEJQA70018-9197 http://dx.doi.org/10.1109/JQE.1982.1071650 Google Scholar

58. S. J. B. Yooet al., “Quasi-phase-matched second harmonic generation in AlGaAs waveguides with periodic domain inversion achieved by wafer bonding,” Appl. Phys. Lett. 66(25), 3410–3412 (1995).APPLAB0003-6951 http://dx.doi.org/10.1063/1.113370 Google Scholar

59. K. L. Vodopyanovet al., “Optical parametric oscillation in quasi-phase-matched GaAs,” Opt. Lett. 29(16), 1912–1914 (2004).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.29.001912 Google Scholar

60. C. Kielecket al., “High-efficiency 20–50 kHz mid-infrared orientation-patterned GaAs optical parametric oscillator pumped by a 2 μm holmium laser,” Opt. Lett. 34(3), 262–264 (2009).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.34.000262 Google Scholar

61. W. C. Hurlbutet al., “Multiphoton absorption and nonlinear refraction of GaAs in the mid-infrared,” Opt. Lett. 32(6), 668–670 (2007).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.32.000668 Google Scholar

62. R. K. FeaverR. D. PetersonP. E. Powers, “Longwave-IR optical parametric oscillator in orientation-patterned GaAs pumped by a 2 μm Tm,Ho:YLF laser,” Opt. Express 21(13), 16104–16110 (2013).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.21.016104 Google Scholar

63. C. Kielecket al., “OP-GaAs OPO pumped by 2 μm Q-switched lasers: Tm;Ho:silica fiber laser and Ho:YAG laser,” Proc. SPIE 7836, 783607 (2010).PSISDG0277-786X http://dx.doi.org/10.1117/12.865217 Google Scholar

64. D. Creedenet al., “Mid-infrared ZnGeP2 parametric oscillator directly pumped by a pulsed 2 μm Tm-doped fiber laser,” Opt. Lett. 33(4), 315–317 (2008).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.33.000315 Google Scholar

65. N. Leindeckeret al., “Octave-spanning ultrafast OPO with 2.6–6.1 μm instantaneous bandwidth pumped by femtosecond Tm-fiber laser,” Opt. Express 20(7), 7046–7053 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.007046 Google Scholar

66. K. F. Leeet al., “Carrier envelope offset frequency of a doubly resonant, nondegenerate, mid-infrared GaAs optical parametric oscillator,” Opt. Lett. 38(8), 1191–1193 (2013).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.38.001191 Google Scholar

67. M. Baudrier-Raybautet al., “Random quasi-phase-matching in bulk polycrystalline isotropic nonlinear materials,” Nature 432(7015), 374–376 (2004). http://dx.doi.org/10.1038/nature03027 Google Scholar

68. X. VidalJ. Martorell, “Generation of light in media with a random distribution of nonlinear domains,” Phys. Rev. Lett. 97(1), 013902 (2006).PRLTAO0031-9007 http://dx.doi.org/10.1103/PhysRevLett.97.013902 Google Scholar

69. E. Andrieuxet al., “500 GHz mode-hop-free idler tuning range with a frequency-stabilized singly resonant optical parametric oscillator,” Opt. Lett. 36(7), 1212–1214 (2011).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.36.001212 Google Scholar

70. S. G. SabouriA. KhorsandiM. Ebrahim-Zadeh, “Power instability of singly resonant optical parametric oscillators: theory and experiment,” Opt. Express 20, 27442–27455 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.027442 Google Scholar

71. W. R. Bosenberget al., “93% pump depletion, 3.5-W continuous-wave, singly resonant optical parametric oscillator,” Opt. Lett. 21(25), 1336–1338 (1996).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.21.001336 Google Scholar

72. K. Schneideret al., “Toward an optical synthesizer: a single-frequency parametric oscillator using periodically poled LiNbO3,” Opt. Lett. 22(17), 1293–1295 (1997).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.22.001293 Google Scholar

73. D. J. M. StothardM. EbrahimzadehM. H. Dunn, “Low-pump-threshold continuous-wave singly resonant optical parametric oscillator,” Opt. Lett. 23(24), 1895–1897 (1998).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.23.001895 Google Scholar

74. M. E. Kleinet al., “Singly resonant continuous-wave optical parametric oscillator pumped by a diode laser,” Opt. Lett. 24(16), 1142–1144 (1999).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.24.001142 Google Scholar

75. K. Deviet al., “Antiresonant ring output-coupled continuous-wave optical parametric oscillator,” Opt. Express 20(17), 19313–19321 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.019313 Google Scholar

76. J. Falk, “Instabilities in the doubly resonant parametric oscillator: a theoretical analysis,” IEEE J. Quantum Electron. 7(6), 230–235 (1971).IEJQA70018-9197 http://dx.doi.org/10.1109/JQE.1971.1076727 Google Scholar

77. C. D. Naborset al., “Efficient, single-axial-mode operation of a monolithic MgO:LiNbO3 optical parametric oscillator,” Opt. Lett. 14(20), 1134–1136 (1989).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.14.001134 Google Scholar

78. L. XuS. ZhangW. Chen, “Tm:YLF laser-pumped periodically poled MgO-doped congruent LiNbO3 crystal optical parametric oscillators,” Opt. Lett. 37(4), 743–745 (2012).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.37.000743 Google Scholar

79. M. E. Kleinet al., “Diode-pumped continuous-wave widely tunable optical parametric oscillator based on periodically poled lithium tantalate,” Opt. Lett. 23(11), 831–833 (1998).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.23.000831 Google Scholar

80. J.-J. Zondyet al., “Output power optimization of continuous-wave, mid-infrared AgGaS2 doubly/triply resonant optical parametric oscillator,” presented at Advanced Solid State Lasers, paper WB6, Optical Society of America, Boston, Massachusetts (31 January 1999). Google Scholar

81. J. TejaN. Wong, “Twin-beam generation in a triply resonant dual-cavity optical parametric oscillator,” Opt. Express 2(3), 65–71 (1998).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.2.000065 Google Scholar

82. I. BreunigD. HaertleK. Buse, “Continuous-wave optical parametric oscillators: recent developments and prospects,” Appl. Phys. B 105(1), 99–111 (2011).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-011-4702-1 Google Scholar

83. M. Ebrahim-Zadehet al., “Breakthroughs in photonics 2012: breakthroughs in optical parametric oscillators,” IEEE Photon. J. 5(2), 700105 (2013).1943-0655 http://dx.doi.org/10.1109/JPHOT.2013.2255268 Google Scholar

84. C. Diederichset al., “Parametric oscillation in vertical triple microcavities,” Nature 440(7086), 904–907 (2006).NATUAS0028-0836 http://dx.doi.org/10.1038/nature04602 Google Scholar

85. C. Y. Wanget al., “Mid-infrared optical frequency combs at 2.5  μm based on crystalline microresonators,” Nat. Commun. 4, 1345 (2013).NCAOBW2041-1723 http://dx.doi.org/10.1038/ncomms2335 Google Scholar

86. S. E. Harris, “Proposed backward wave oscillation in the infrared,” Appl. Phys. Lett. 9(3), 114–116 (1966).APPLAB0003-6951 http://dx.doi.org/10.1063/1.1754668 Google Scholar

87. C. CanaliasV. Pasiskevicius, “Mirrorless optical parametric oscillator,” Nat. Photonics 1(8), 459–462 (2007).1749-4885 http://dx.doi.org/10.1038/nphoton.2007.137 Google Scholar

88. J. B. Khurgin, “Optical parametric oscillator: Mirrorless magic,” Nat. Photonics 1(8), 446–447 (2007).1749-4885 http://dx.doi.org/10.1038/nphoton.2007.131 Google Scholar

89. D. G. Lancasteret al., “Real-time measurements of trace gases using a compact difference-frequency-based sensor operating at 3.5 μm,” Appl. Phys. B 67(3), 339–345 (1998).APBOEM0946-2171 http://dx.doi.org/10.1007/s003400050513 Google Scholar

90. Z. G. Guanet al., “Vertical lidar sounding of atomic mercury and nitric oxide in a major Chinese city,” Appl. Phys. B 101(1–2), 465–470 (2010).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-010-4166-8 Google Scholar

91. F. Kuhnemannet al., “Photoacoustic trace-gas detection using a cw single-frequency parametric oscillator,” “Photoacoustic trace-gas detection using a cw single-frequency parametric oscillator,” Appl. Phys. B 66(6), 741–745 (1998).APBOEM0946-2171 http://dx.doi.org/10.1007/s003400050461 Google Scholar

92. M. W. Toddet al., “Application of mid-infrared cavity-ringdown spectroscopy to trace explosives vapor detection using a broadly tunable (6–8 μm) optical parametric oscillator,” Appl. Phys. B 75(2–3), 367–376 (2002).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-002-0991-8 Google Scholar

93. Y. HeM. HipplerM. Quack, “High-resolution cavity ring-down absorption spectroscopy of nitrous oxide and chloroform using a near infrared cw diode laser,” Chem. Phys. Lett. 289(5–6), 527–534 (1998).CHPLBC0009-2614 http://dx.doi.org/10.1016/S0009-2614(98)00424-2 Google Scholar

94. D. Zhaoet al., “Mid-infrared continuous wave cavity ring-down spectroscopy of a pulsed hydrocarbon plasma,” Chem. Phys. Lett. 565, 132–137 (2013).CHPLBC0009-2614 http://dx.doi.org/10.1016/j.cplett.2013.02.025 Google Scholar

95. B. A. PaldusA. A. Kachanov, “An historical overview of cavity-enhanced methods,” Can. J. Phys. 83(10), 975–999 (2005).CJPHAD0008-4204 http://dx.doi.org/10.1139/p05-054 Google Scholar

96. A. Marianet al., “United time-frequency spectroscopy for dynamics and global structure,” Science 306(5704), 2063–2068 (2004).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.1105660 Google Scholar

97. F. Adleret al., “Phase-stabilized, 1.5 W frequency comb at 2.8–4.8 μm,” Opt. Lett. 34(9), 1330–1332 (2009).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.34.001330 Google Scholar

98. M. W. Haakestadet al., “Intracavity trace molecular detection with a broadband mid-IR frequency comb source,” J. Opt. Soc. Am. B 30(3), 631–640 (2013).JOBPDE0740-3224 http://dx.doi.org/10.1364/JOSAB.30.000631 Google Scholar

99. A. Marandiet al., “Coherence properties of a broadband femtosecond mid-IR optical parametric oscillator operating at degeneracy,” Opt. Express 20(7), 7255–7262 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.007255 Google Scholar

100. T. Langet al., “High power ultra-widely tuneable femtosecond pulses from a non-collinear optical parametric oscillator (NOPO),” Opt. Express 20(2), 912–917 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.000912 Google Scholar

101. M. J. Thorpeet al., “Broadband cavity ringdown spectroscopy for sensitive and rapid molecular detection,” Science 311(5767), 1595–1599 (2006).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.1123921 Google Scholar

102. M. J. ThorpeJ. Ye, “Cavity-enhanced direct frequency comb spectroscopy,” Appl. Phys. B 91(3–4), 397–414 (2008).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-008-3019-1 Google Scholar

103. F. Adleret al., “Cavity-enhanced direct frequency comb spectroscopy: technology and applications,” Annu. Rev. Anal. Chem. 3, 175–205 (2010).ARACFU1936-1327 http://dx.doi.org/10.1146/annurev-anchem-060908-155248 Google Scholar

104. M. J. Thorpeet al., “Cavity-enhanced optical frequency comb spectroscopy: application to human breath analysis,” Opt. Express 16(4), 2387–2397 (2008).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.16.002387 Google Scholar

105. M. W. Haakestadet al., “Intracavity trace molecular detection with a broadband mid-IR frequency comb source,” J. Opt. Soc. Am. B 30(3), 631–640 (2013).JOBPDE0740-3224 http://dx.doi.org/10.1364/JOSAB.30.000631 Google Scholar

106. D. Richteret al., “Field measurements of volcanic gases using tunable diode laser based mid-infrared and Fourier transform infrared spectrometers,” Opt. Lasers Eng. 37(2–3), 171–186 (2002).OLENDN0143-8166 http://dx.doi.org/10.1016/S0143-8166(01)00094-X Google Scholar

107. L. B. FlanaganJ. R. Ehleringer, “Ecosystem-atmosphere CO2 exchange: interpreting signals of change using stable isotope ratios,” Trend Ecol. Evol. 13(1), 10–14 (1998).TREEEQ0169-5347 http://dx.doi.org/10.1016/S0169-5347(97)01275-5 Google Scholar

108. F. KeilmannCh. GohleR. Holzwarth, “Time-domain mid-infrared frequency-comb spectrometer,” Opt. Lett. 29(13), 1542–1544 (2004).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.29.001542 Google Scholar

109. I. CoddingtonW. C. SwannN. R. Newbury, “Coherent multiheterodyne spectroscopy using stabilized optical frequency combs,” Phys. Rev. Lett. 100(1), 013902 (2008).PRLTAO0031-9007 http://dx.doi.org/10.1103/PhysRevLett.100.013902 Google Scholar

110. F. Zhuet al., “Real-time dual frequency comb spectroscopy in the near infrared,” Appl. Phys. Lett. 102(12), 121116 (2013).APPLAB0003-6951 http://dx.doi.org/10.1063/1.4799282 Google Scholar

111. F. Adleret al., “Mid-infrared Fourier transform spectroscopy with a broadband frequency comb,” Opt. Express 18(21), 21861–21872 (2010).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.18.021861 Google Scholar

112. Z. ZhangT. GardinerD. T. Reid, “Mid-infrared dual-comb spectroscopy with an optical parametric oscillator,” Opt. Lett. 38(16), 3148–3150 (2013).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.38.003148 Google Scholar

113. C.-H. Liet al., “A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s1,” Nature 452(7178), 610–612 (2008).NATUAS0028-0836 http://dx.doi.org/10.1038/nature06854 Google Scholar

114. T. Steinmetzet al., “Laser frequency combs for astronomical observations,” Science 321(5894), 1335–1337 (2008).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.1161030 Google Scholar

115. O. KokabeeA. Esteban-MartinM. Ebrahim-Zadeh, “Extended-cavity, tunable, GHz-repetition-rate femtosecond optical parametric oscillator pumped at 76 MHz,” Opt. Express 17(18), 15635–15640 (2009).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.17.015635 Google Scholar

116. T. Ideguchiet al., “Coherent Raman spectro-imaging with laser frequency combs,” Nature 502(7471), 355–358 (2013).NATUAS0028-0836 http://dx.doi.org/10.1038/nature12607 Google Scholar

117. A. Esteban-Martinet al., “Frequency-modulation-mode-locked optical parametric oscillator,” Opt. Lett. 37(1), 115–117 (2012).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.37.000115 Google Scholar

118. K. DeviS. Ch. KumarM. Ebrahim-Zadeh, “Mode-locked, continuous-wave, singly resonant optical parametric oscillator,” Opt. Lett. 37(18), 3909–3911 (2012).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.37.003909 Google Scholar

119. T. J. KippenbergR. HolzwarthS. A. Diddams, “Microresonator-based optical frequency combs,” Science 332(6029), 555–559 (2011).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.1193968 Google Scholar

120. B. Guoet al., “Laser-based mid-infrared reflectance imaging of biological tissues,” Opt. Express 12(1), 208–219 (2004).OPEXFF1094-4087 http://dx.doi.org/10.1364/OPEX.12.000208 Google Scholar

121. V. A. Serebryakovet al., “Medical applications of mid-IR lasers. Problems and prospects,” J. Opt. Technol. 77(1), 6–17 (2010).JOTEE41070-9762 http://dx.doi.org/10.1364/JOT.77.000006 Google Scholar


Jiahui Peng received his BS in optics from Nankai University, and his PhD in physics from Texas A&M University. After working as a postdoctoral fellow in NRC-uOttawa Joint Attosecond Science Laboratory, he is working as a research scientist at IMRA America Inc.

© The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
Jiahui Peng, Jiahui Peng, } "Developments of mid-infrared optical parametric oscillators for spectroscopic sensing: a review," Optical Engineering 53(6), 061613 (27 February 2014). https://doi.org/10.1117/1.OE.53.6.061613 . Submission:

Back to Top