1 July 2013 Mode-locked 2-μm wavelength fiber laser using a graphene-saturable absorber
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Soliton-like pulses with a 1984-nm center wavelength are produced from a Tm-doped mode-locked fiber laser. The linear cavity has a graphene saturable absorber mirror at one end and a fiber Bragg grating as the output coupler. The laser operates without dispersion compensation, and the repetition rate was tuned from 20 to 5 MHz by the addition of SMF-28 fiber. The dry transfer process used to place the graphene on a mirror could be extended to any optical substrate. This enables integration of graphene with optics such as an optical window coated with a graphene filter or a graphene-saturable absorber placed directly on a semiconductor laser facet.



Graphene is an interesting optical material. It possesses a nearly wavelength independent linear absorption from the visible through the far infrared, while absorbing a large amount (2.3%) of light per monolayer.1 With a finite number of carriers in the monolayer, Pauli blocking enables graphene to exhibit optical-saturable absorption at low saturation intensities. This effect was first demonstrated and used as a mode-locking element for a fiber laser.2

Since then, mode-locked lasers have been created using graphene as a saturable absorber at wavelengths in the near IR. Theory predicts graphene’s performance as a saturable absorber at wavelengths beyond 1.55 μm.9 Graphene’s broadband performance has been shown by a few groups by using it as a saturable absorber to mode-lock lasers at wavelengths longer than 1.55 μm.3,1011.12 This is useful since relatively few semiconductor-saturable absorbers (SESAMs) have been created in the mid-infrared region (e.g., wavelengths beyond 2.2 μm). The semiconductor-saturable absorber materials used in this region are GaAs,11 InGaAs,13 GaInSb/GaSb,14 and InAs/GaSb.1516.17 In addition, graphene’s optical damage threshold is high enough (near 100GW/cm2)18 to allow saturable absorption without the concern of damaging the graphene.

While graphene-based fiber lasers have been mode locked at 1 and 1.5 μm, there are only a few reports of graphene as a saturable absorber at 2 μm, such as: two Q-switched lasers,11,19 a Q-switched and mode-locked laser,3 a mode-locked solid-state laser,10 and one (recent) report of graphene’s use in mode-locked fiber lasers at a wavelength greater than 1.6 μm.12

Of the reported graphene-saturable absorbers, few are fabricated as saturable absorber mirrors (SAMs). Graphene-based SAMs have been fabricated via (1) dispersion of graphene in a solution with poly(methyl methacrylate)20 and polyvinyl-alcohol,21 (2) liquid-phase exfoliation of small area (20μm) flakes,8,22,23 or (3) chemical vapor deposition on copper foils and transferral to a mirror.3,10

Until now, epitaxially grown graphene on silicon carbide (SiC) was used as a saturable absorber only in Q-switched lasers,9,19,24,25 and not in mode-locked lasers. Here, we report a graphene SAM fabricated using large-area epitaxially grown graphene on SiC and transferred by a unique dry transfer process to an Ag mirror. Our transfer process overcomes an obstacle of growing high-quality large-area graphene and transferring it to substrates suitable for optical devices with area of 1×1cm2. This is a tremendous advantage for creating continuous graphene layers over large areas that are unachievable with the popular method of sonication of graphite.8,22,23 In addition, using graphene synthesized on SiC opens up a potential avenue for mass production of saturable absorber feedstock. Such an approach will benefit from the obvious economies of scale associated with the commercial business of GaN on SiC LEDs as well as the increasingly important low voltage (600 V) SiC current switches that are of interest for applications such as in the auto industry.

Using this graphene-based SAM, we demonstrate a mode-locked Tm-doped fiber laser in a linear cavity, eliminating additional optical elements used in the more common ring-cavity fiber lasers. Our laser produces soliton-like pulses, whose repetition rate is varied by increasing the cavity length with additional SMF-28 fiber. This laser system provides a path for compact portable sources for spectroscopy in the molecular fingerprint region,26 lab-on-a-chip sensors, and other applications currently served by large laboratory lasers.



Practical graphene optical devices often require large, uniform, high-quality films measuring at least 5×5mm2 and deposited on optically compatible substrates. The most promising synthesis methods for this are graphene epitaxially produced by sublimation of Si from SiC substrates.27 Graphene layers were epitaxially grown on the carbon face of semi-insulating on-axis 6H-SiC substrates. The process was performed at 1600°C under high vacuum (<104mbar).28 A transmissive scanning optical probe characterized the epitaxially grown graphene as a multilayer structure containing 13±3 layers.

The saturable absorption for multilayer epitaxially grown graphene sample on SiC was measured using degenerate femtosecond optical pump-probe spectroscopy at 800 nm. The results, shown in Fig. 1, demonstrate that in response to a 100-fs optical pulse the multilayer graphene sample undergoes a 2% increase in transmission (Fig. 1). Different graphene-saturable absorber growth methods have demonstrated variability in performance. Recently, the modulation depth of graphene-saturable absorption was modified by doping.29 Our graphene sample’s recovery to the steady-state transmission is described by a 0.15-ps exponential decay. The pump pulse’s energy was 25 pJ and produced a 9MW/cm2 optical irradiance on the graphene sample. Our results agree with other measured saturation intensities of 0.6 to 0.7MW/cm2 for multilayer graphene-saturable absorbers.2

Fig. 1

Multilayer graphene response to 100-fs optical pump-probe measurement demonstrates saturable absorption with a 2% increase in transmission.


The graphene was transferred onto a commercial Ag optical mirror via a dry transfer process.30 This removes the epitaxial graphene from the C-face of 6H-SiC and places it onto the mirror using thermal release tape. The transfer of our multilayer film resulted in graphene thicknesses ranging from 0 to 13 layers of graphene across the 25-mm diameter Ag mirror due to adhesion difficulty with the commercial Ag mirror. Surprisingly, this provided an advantage since the graphene SAM has spatially variable saturable absorption characteristics that can be tuned by laterally moving the mirror (as explained later).

A linear fiber laser was constructed using a wavelength-division multiplexer (WDM, Lightel 793/1980) to couple the pump light into a 0.7-m Tm-doped fiber (Nufern SM-TSF-9/125), as shown in Fig. 2. A fiber Bragg grating (FBG) with 80% reflection at 1984 nm and >2-nm bandwidth was spliced to the WDM and operated as an output coupler. Following the Tm-fiber, several lengths of SMF-28 single-mode fiber were used to vary the cavity length, and these were butt coupled to the graphene SAM. A five-axis stage controlled the graphene SAM’s coupling to the laser cavity and enabled laterally moving the SAM to expose different areas, thereby changing the SAM characteristics.

Fig. 2

(a) An image of the graphene transferred to the Ag mirror creating the saturable absorber mirror (SAM). (b) A schematic diagram of the linear fiber laser cavity shows the graphene-based SAM (g-SAM), an optional length of SMF-28 fiber, 0.7-m Tm-doped fiber amplifier, wavelength-division multiplexer (WDM), pump laser, and fiber Bragg grating (FBG) output coupler.


Without the SAM, a 796-nm pump laser was used to obtain the amplified spontaneous emission (ASE) spectrum following the 80% FBG output coupler. Figure 3(a) shows the broad 200-nm-wide ASE spectrum centered at 1820 nm with a 3-nm-wide dip in the curve at 1984 nm due to the FBG reflection, as measured by a Yokogawa AQ 6375 optical spectrum analyzer. The ASE peak <1900nm is indicative of core-pumped Tm-doped fiber, whereas a cladding-pumped amplifier would have a red-shifted ASE peak near 1950 nm.31 (Note: Some residual transmitted 796-nm pump is observed near 1600 nm due to second-order diffraction in the spectrometer, and the apparent spectral noise from 1800 to 1900 nm is due to atmospheric absorption lines within the spectrometer).

Fig. 3

Optical spectra of the amplified spontaneous emission (ASE) of the Tm fiber (a) and mode-locked laser (b) with inset zooming in on the laser’s peak wavelength.


The graphene SAM was installed by butt coupling with a SMF-28 fiber. Continuous wave (cw) lasing was achieved at 1984 nm when the SAM was positioned with only the Ag mirror (i.e., in a position with no graphene on the mirror). The losses in the cavity due to the WDM (50% insertion loss at 1984 nm), the output coupler, and the coupling loss at the SAM made it difficult to achieve even cw lasing. Following this, the absorption spectra of the Tm fiber was measured with a white-light source and established 788 nm as the optimal absorption for the Tm fiber. The 796-nm pump was then replaced by a 788-nm fiber-coupled cw Ti:sapphire laser with up to 350 mW coupled into the cavity. This provided >10-mW cw output from the fiber laser at 1984 nm, which is >150nm from the Tm fiber’s ASE peak.

Lateral motion of the graphene SAM shifted the coupling from the Ag mirror to the graphene coating. In positions with the maximum number of graphene layers, no lasing occurred. In positions with no graphene, cw lasing occurred. In the transition region between no graphene and a few layers of graphene, mode-locked operation occurred. Spectra of the mode-locked operation, shown in Fig. 3(b), demonstrate the mode-locked fiber laser’s 1.7-nm spectral width. The spectral wings exhibit Kelly sidebands32 seen in soliton-like saturable absorber lasers that are caused by cavity-enhanced dispersive waves arising from discrete gain, loss, and dispersion in the laser cavity.33 The broad ASE background is also visible, but is five orders of magnitude weaker than the peak mode-locked signal and can be further minimized by using a bandpass filter (much like the FBG in our laser cavity).

Different lengths of SMF-28 were used to achieve variable repetition rates. Pulsed output was measured with a >100-MHz bandwidth IR detector (Vigo System PVM-10.6). Without any additional fiber, the laser had a 19.6-MHz repetition rate, shown in Fig. 4, with a mean temporal spacing of 51 ns and a standard deviation of 0.11 ns, demonstrating a stability better than 0.21% (as measured by a LeCroy WaveRunner oscilloscope). Increasing the cavity length by adding an additional 11 m of SMF-28 fiber produced mode-locked pulses at a 4.9-MHz repetition rate with a stability better than 0.06%. This stability improvement at longer cavity lengths may be caused by slightly higher energy pulses at the saturable absorber, which is offset by the increased attenuation of the additional fiber. At wavelengths near 2 μm, the loss of SMF-28 fiber is large even when wound with diameters >30cm. For lengths >11m, the SMF-28 produced intracavity losses that exceeded the system gain, and thus, quenched the laser operation (even cw operation).

Fig. 4

The temporal response of the detected optical pulse trains shows variable repetition rates of the 19.6-MHz cavity (a) and 4.9-MHz extended cavity (b) using 11-m SMF-28 fiber.


With the laser mode-locked, increasing the pump power did not increase pulse’s amplitude. Instead, increasing the pump power introduced additional pulses within the cavity repetition rate, at which point the output power would increase in steps of approximately 0.5 mW. Increasing the pump power further increased the number of pulses per cavity round trip with commensurate steps in the output power. With only two or three pulses per cavity round-trip period, the pulses were stable in time (i.e., their temporal spacing remained fixed). With more than three pulses per round-trip period, the extra pulses were erratic in time, drifting within the laser cavity’s round-trip period. Other graphene-based Er-doped fiber lasers near 1550 nm have also demonstrated multiple-soliton dynamics.5 During multipulse operation, all of the laser pulses had the same amplitude, which was the same pulse amplitude observed when in single-pulse operation.


Results and Discussion

Graphene’s saturable absorption characteristics are theoretically predicted to occur over a broad wavelength range.9 Our epitaxially grown graphene demonstrated saturable absorption at 800 and 1984 nm. At 800 nm, our pump-probe setup showed a 2% increase in transmission for a 9MW/cm2 optical irradiance. At 1984 nm, the graphene showed mode-locking performance in our laser. To calculate the optical irradiance on the graphene at 1984 nm, we assume that our intracavity power at the output coupler (Pout/20%10mWave) is the same as was present at the graphene-saturable absorber, thereby producing an irradiance on the graphene of 800MW/cm2. This is much greater than the saturation intensity of the graphene2 and, combined with the mode-locking of our laser, confirms operation of our graphene-saturable absorber at 1984 nm.

Our laser does not contain any dispersion compensation and, therefore, operates in the anomalous dispersion regime. Pulse evolution in mode-locked lasers occurs through interplay between anomalous group-velocity dispersion (GVD) and nonlinearity (Kerr) within the fiber. When constructed entirely from anomalous-dispersion fiber, this laser can support solitons. With the 11-m SMF-28 extension, the laser cavity is approximately 20 m long (single pass). The GVD of SMF-28 at a 2-μm wavelength is 0.12ps2/m,34 which provides a rather large round-trip cavity dispersion of 4ps2.

To investigate the soliton-like properties of this laser, we use the ratio of the dispersion to the nonlinear lengths (LD/LNL) to define the soliton order.35 For a fundamental soliton, the dispersion and nonlinear lengths are equal where the dispersion length (LD=T02/|β2|) and nonlinear lengths [LNL=1/(γP0)]] can be calculated if we know the fiber’s GVD (β2), the pulse width (T0), the nonlinear parameter (γ), and the peak-pulse power (P0).

The nonlinear parameter can be calculated as γ=2πn2/(Aeffλ), where we use λ=2μm, n2=2.2×1020m2/W,35 and assume a 15% larger effective area for SMF-28 at 2 μm Aeff=100μm2, providing γ=7×104W1·m1. Our 1.7-nm spectral width would produce a transform-limited hyperbolic secant pulse with a T0=2.4/1.763-ps pulsewidth. For these parameters, the peak pulse power of a soliton formed in this cavity would be 90 W, with a 1.1-mW average power at a 5-MHz repetition rate.

Our average output power at 5-MHz is 2mW, providing an average intracavity power of 10mW (Pout/20%). While this number is somewhat higher than our calculated value, it is reasonable due to the high cavity losses and the uncertainty of the gain fiber parameters. In addition, when there are multiple pulses within the cavity the output power increases by 0.5mW per pulse, which is closer to the 1.1-mW average power calculated for the intracavity soliton.



Mode-locked optical pulses were produced by using graphene as a saturable absorber in a 1984-nm Tm-based fiber laser. The linear geometry fiber laser achieved lasing at a wavelength >150nm from the ASE peak by using a FBG at 1984 nm. The 2-μm wavelength fiber technology is improving, but it is not as refined as that of 1550-nm telecommunication technology. Even with these limitations, we were able to overcome the cavity losses and form mode-locked pulse trains at 5- to 20-MHz repetition rates with output powers from 2 to 8 mW. The mode-locked fiber laser operated in the anomalous dispersion regime, without dispersion compensation, and soliton-like operation was observed. Our graphene transfer process enables bonding graphene to any substrate, and in this case bonding to an Ag mirror produced a wavelength-independent SAM, unlike SESAMs which are engineered for specific wavelengths. In addition, due to material issues SESAMs are difficult to engineer at wavelengths longer than 2 μm; thus, graphene may play a future role as a SAM for creating mode-locked lasers in the mid-IR region. This laser demonstrates the potential for portable mode-locked laser sources in the mid-IR.


The authors thank Rafael Gattass and Catalin Florea for useful discussions and borrowed equipment, and Jerry Chappell of Teracomm for use of the AQ 6375. This work was supported by the Office of Naval Research. Luke O. Nyakiti gratefully acknowledges support from the ASEE for postdoctoral fellowship support.


1. R. R. Nairet al., “Fine structure constant defines visual transparency of graphene,” Science 320(5881), 1308 (2008).SCIEAS0036-8075 http://dx.doi.org/10.1126/science.1156965 Google Scholar

2. Q. Baoet al., “Atomic-layer graphene as a saturable absorber for ultrafast pulsed lasers,” Adv. Funct. Mater. 19(19), 3077–3083 (2009).AFMDC61616-3028 http://dx.doi.org/10.1002/adfm.v19:19 Google Scholar

3. G. Q. Xieet al., “Graphene saturable absorber for Q-switching and mode locking at 2 μm wavelength,” Opt. Mater. Express 2(6), 878–883 (2012).OMEPAX 2159-3930 http://dx.doi.org/10.1364/OME.2.000878 Google Scholar

4. D. Popaet al., “Sub 200 fs pulse generation from a graphene mode-locked fiber laser,” Appl. Phys. Lett. 97(20), 203106 (2010).APPLAB0003-6951 http://dx.doi.org/10.1063/1.3517251 Google Scholar

5. Y. Menget al., “Multiple-soliton dynamic patterns in a graphene mode-locked fiber laser,” Opt. Express 20(6), 6685–6692 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.006685 Google Scholar

6. P. L. Huanget al., “Stable mode-locked fiber laser based on CVD fabricated graphene saturable absorber,” Opt. Express 20(3), 2460–2465 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.002460 Google Scholar

7. A. MartinezS. Yamashita, “10 GHz fundamental mode fiber laser using a graphene saturable absorber,” Appl. Phys. Lett. 101(4), 041118 (2012).APPLAB0003-6951 http://dx.doi.org/10.1063/1.4739512 Google Scholar

8. J.-L. Xuet al., “Graphene saturable absorber mirror for ultra-fast-pulse solid-state laser,” Opt. Lett. 36(10), 1948–1950 (2011).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.36.001948 Google Scholar

9. G. Xinget al., “The physics of ultrafast saturable absorption in graphene,” Opt. Express 18(5), 4564–4573 (2010).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.18.004564 Google Scholar

10. J. Maet al., “Graphene mode-locked femtosecond laser at 2 μm wavelength,” Opt. Lett. 37(11), 2085–2087 (2012).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.37.002085 Google Scholar

11. J. LiuQ. WangP. Wang, “High average power picosecond pulse generation from a thulium-doped all-fiber MOPA system,” Opt. Express 20(20), 22442–22447 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.022442 Google Scholar

12. M. Zhanget al., “Tm-doped fiber laser mode-locked by graphene-polymer composite,” Opt. Express 20(22), 25077–25084 (2012).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.20.025077 Google Scholar

13. R. C. Sharpet al., “190-fs passively mode-locked thulium fiber laser with a low threshold,” Opt. Lett. 21(12), 881–883 (1996).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.21.000881 Google Scholar

14. S. Kivistöet al., “Tunable Raman soliton source using mode-locked Tm-Ho fiber laser,” IEEE Photon. Technol. Lett. 19(12), 934–936 (2007).IPTLEL1041-1135 http://dx.doi.org/10.1109/LPT.2007.898877 Google Scholar

15. C. R. Pollocket al., “Mode locked, and Q-switched Cr:ZnSe laser using a semiconductor saturable absorbing mirror (SESAM),” in OSA Trends Opt. Photon. Ser., C. DenmanI. Sorokina, Eds., Vol. 98, pp. 252–256, Advanced Solid-State Photonics (ASSP), Vienna, Austria (2005). Google Scholar

16. I. T. SorokinaE. SorokinT. J. Carrig, “Femtosecond pulse generation from a sesam mode-locked CrZnSe laser,” in Conf. Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006 (2006). Google Scholar

17. B. Bernhardtet al., “Mid-infrared dual-comb spectroscopy with 2.4 μm Cr2+ZnSe femtosecond lasers,” Appl. Phys. B Lasers Opt. 100(1), 3–8 (2010).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-010-4080-0 Google Scholar

18. M. Currieet al., “Quantifying pulsed laser induced damage to graphene,” Appl. Phys. Lett. 99(21), 211909 (2011).APPLAB0003-6951 http://dx.doi.org/10.1063/1.3663875 Google Scholar

19. Q. Wanget al., “Graphene on SiC as a Q-switcher for a 2 μm laser,” Opt. Lett. 37(3), 395–397 (2012).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.37.000395 Google Scholar

20. M. Jianget al., “Graphene-based passively Q-switched diode-side-pumped NdYAG solid laser,” Opt. Commun. 284(22), 5353–5356 (2011).OPCOB80030-4018 http://dx.doi.org/10.1016/j.optcom.2011.07.063 Google Scholar

21. J. Liuet al., “Stable nanosecond pulse generation from a graphene-based passively Q-switched Yb-doped fiber laser,” Opt. Lett. 36(20), 4008–4010 (2011).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.36.004008 Google Scholar

22. B. V. CunningC. L. BrownD. Kielpinski, “Low-loss flake-graphene saturable absorber mirror for laser mode-locking at sub-200-fs pulse duration,” Appl. Phys. Lett. 99(26), 261109 (2011).APPLAB0003-6951 http://dx.doi.org/10.1063/1.3672418 Google Scholar

23. X.-L. Liet al., “Large energy laser pulses with high repetition rate by graphene Q-switched solid-state laser,” Opt. Express 19(10), 9950–9955 (2011).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.19.009950 Google Scholar

24. H. Shenet al., “Passively Q-switched NdKLu(WO4)2 laser at 1355 nm with graphene on SiC as saturable absorber,” Appl. Phys. Express 5(9), 092703 (2012).1882-0778 Google Scholar

25. C. Gaoet al., “Resonantly pumped 1.645 μm high repetition rate ErYAG laser Q-switched by a graphene as a saturable absorber,” Opt. Lett. 37(4), 632–634 (2012).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.37.000632 Google Scholar

26. E. Sorokinet al., “Sensitive multiplex spectroscopy in the molecular fingerprint 2.4 μm region with a Cr2+ZnSe femtosecond laser,” Opt. Express 15(25), 16540–16545 (2007).OPEXFF1094-4087 http://dx.doi.org/10.1364/OE.15.016540 Google Scholar

27. C. Bergeret al., “Ultrathin epitaxial graphite: 2D electron gas properties and a route toward graphene-based nanoelectronics,” J. Phys. Chem. 108(52), 19912–19916 (2004).JPCHAX0022-3654 http://dx.doi.org/10.1021/jp040650f Google Scholar

28. B. L. VanMilet al., “Graphene formation on SiC substrates,” Mater. Sci. Forum 615–617, 211–214 (2009).MSFOEP0255-5476 http://dx.doi.org/10.4028/www.scientific.net/MSF.615-617 Google Scholar

29. C.-C. LeeJ. M. MillerT. R. Schibli, “Doping-induced changes in the saturable absorption of monolayer graphene,” Appl. Phys. B Lasers Opt. 108(1), 129–135 (2012).APBOEM0946-2171 http://dx.doi.org/10.1007/s00340-012-5095-5 Google Scholar

30. J. D. Caldwellet al., “Technique for the dry transfer of epitaxial graphene onto arbitrary substrates,” ACS Nano 4(2), 1108–1114 (2010).1936-0851 http://dx.doi.org/10.1021/nn901585p Google Scholar

31. Q. Wanget al., “Mode-locked Tm-Ho-codoped fiber laser at 2.06 μm,” IEEE Photon. Technol. Lett. 23(11), 682–684 (2011).IPTLEL1041-1135 http://dx.doi.org/10.1109/LPT.2011.2123880 Google Scholar

32. S. M. J. Kelly, “Characteristic sideband instability of periodically amplified average soliton,” Electron. Lett. 28(8), 806–807 (1992).ELLEAK0013-5194 http://dx.doi.org/10.1049/el:19920508 Google Scholar

33. M. L. DennisI. N. Duling III, “Experimental study of sideband generation in femtosecond fiber lasers,” IEEE J. Quant. Electron. 30(6), 1469–1477 (1994).IEJQA70018-9197 http://dx.doi.org/10.1109/3.299472 Google Scholar

34. J. Genget al., “Kilowatt-peak-power, single-frequency, pulsed fiber laser near 2 μm,” Opt. Lett. 36(12), 2293–2295 (2011).OPLEDP0146-9592 http://dx.doi.org/10.1364/OL.36.002293 Google Scholar

35. G. P. Agrawal, Nonlinear Fiber Optics, 3rd ed., Academic Press, San Diego (2001). Google Scholar

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© 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.
Marc Currie, Marc Currie, Travis J. Anderson, Travis J. Anderson, Virginia D. Wheeler, Virginia D. Wheeler, Luke O. Nyakiti, Luke O. Nyakiti, Nelson Y. Garces, Nelson Y. Garces, Rachael L. Myers-Ward, Rachael L. Myers-Ward, Charles R. Eddy, Charles R. Eddy, Fritz J. Kub, Fritz J. Kub, D. Kurt Gaskill, D. Kurt Gaskill, } "Mode-locked 2-μm wavelength fiber laser using a graphene-saturable absorber," Optical Engineering 52(7), 076101 (1 July 2013). https://doi.org/10.1117/1.OE.52.7.076101 . Submission:

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