In this paper, high power and high efficiency operation of an all solid state, quasi-continuous-wave, Ti: sapphire laser is obtained with a laser diode pumped frequency doubled Nd: YAG laser. Discussing the output characters with three kinds of oscillate cavity, we acquire high output power, high light quality Ti: sapphire laser with flat to flat oscillate cavity. The maximum output power is 6.1W at 797nm with pump power of 27W, conversion efficiency is 22.6%, FWHM is 38.4ns and M2 is 3.6. Tuning by birefringent filter, all solid state titanium doped sapphire laser's output wavelength is from 750~950nm and average output power is 4.7W.
Pump-tuning method is very important and useful to OPO because it can relieve the OPO of any requirement for crystal translation or temperature variation. In this way, using PPLN crystal with poled period of 20.5mm, 1017~3384nm quasi-continuous-wave output is obtained pumped by Ti: sapphire laser which is tuned from 770 to 820nm. The maximum output power is 1.9W at 1208nm and conversion efficiency is 32%.OPO's average output power is 1.3W in whole output wavelength.
We present a theoretical study of optical bistability and differential amplification, arising as a consequence of the nonlinear Kerr effect in mutually coupled nonlinear microcavity resonators. The dependence of the bistability and differential amplification on various parameters of the coupling range and the resonators is investigated. Multiple closely spaced bistability of the internal intensity in the microresonator is found with appropriate parameters. The results may be useful for a complex logic, memory or switch operation system.
Based on near-NCPM (Non Critical Phase Matching) design, type I temperature phase matching of MgO doped LiNbO<sub>3</sub> OPO (Optic Parametric Oscillation) with selected cutting angle at 82 degree. Replacing NCPM with near-NCPM to limit the operation temperature range to a relative low level, a temperature tuned OPO pumped by 532 nm is developed and 800-1700 nm tunable signal lights are achieved. Output pulse energy is higher than 5mJ by a pumping laser of 58 mJ, 532 nm and 6 ns. With frequency doubling of OPO light through a 24.5 degree cut BBO crystal, 2 mJ, 400-800 nm output is obtained by a 19.8-29.2 degree rotating accordingly. The threshold of pump peak intensity for OPO is 57.3 MW/cm<sup>2</sup>. On the position of two times of threshold energy, SRO conversion efficiency is over 11%.
Pico-second solid-state lasers with multi-watt average power and multi-kilowatt peak power are required for numerous applications such as UV generation and pumping of optical parametric oscillators for RGB laser TV display. In the past few years laser diode bars as pump source with continue output power of hundreds watts or more have become commercially available. LD side pumping YAG laser module can be used to generate high reputation mode locked output pulse with SESAM (Semiconductor Saturable Absorber Mirror) as an end cavity mirror. In this paper, we demonstrate an all solid-state mode-locked YAG laser with three-mirror folded cavity with a SESAM mirror, 80MHz pulse rate, about 10ps pulse width, and 2W 1064 nm output power. Thermal effect of laser rod, and polarization of intra-cavity beam are considered in laser cavity design. The enhancement of laser performance and decreasing Q switching effect are discussed. Further investigation is greatly needed.
High-power red laser are of great interest in the fields of medical application, laser display and also as a pumping source for tunable lasers such as Cr:LiSAF. This letter reports the generation of a 12W Q-CW red laser beam by intracavity frequency-doubling of a Nd:YAG laser operating at 1.3μm with a KTP crystal. A laser module that consisting of a Nd:YAG rod side-pumped by thirty 20W LDs of a triangle radial pump geometry, a acousto-optic Q switch and a KTP crystal were used in the experiment. Because the efficiency of SHG is sensitive to the type II phase-matching angles of KTP, we calculate the value of phase-matching angles according to several of Sellemier equations of KTP, and modify the phase-matching angles to θ=59.9° and φ=0° by experiment. The maximum average power of 12W of red laser is achieved at 10KHz when the pump power of LDs is about 470W.
Based oii quantum theory and combined with the nonlinear effects of both Stimulated Raman Scattering (SRS) and Simulated FoLirth-photon Mixing (SFPM), the correlation among the pump, the input signal and the output in the Raman amplified fiber-optic transmission systems, is calculated and analyzed. Synthesize the correlation function group and program the corresponding software package. And when the ratio of the pump to the Stocks waves is in a certain field, the correlation is comparatively high, the corresponding input signal amplification multiple ? gets to the extreme field. And when the ratio of the pump to the Stocks waves is oversize or undersize, the correlation is decreasing correspondingly. The conclusion of this letter is benefit to optimize the design and experimental research of Fiber Raman Amplifier (FRA).
A high power intracavity frequency doubled Nd:YAG laser with KTP crystal and A-O Q-switcher pumped by 1600 Watt-808 nm laser diodes and its thermal effect are discussed. Also we proved that the title angle of KTP crystal can be to compensate for the phase mismatching and to solve the problem of the drop of green laser output power along with the increasing temperature of KTP crystal. Then based on optical parametric oscillator (KTP-OPO) pumped by 532 nm laser and their frequency doubling (with KTP and BBO) a Watt-level red and blue laser system which would be provided as RGB laser projection display are described.
Thermal lens effect is a very important factor in designing stable resonators for high-power solid-state laser pumped by laser diodes. In a symmetric plane-parallel resonator , if the thermal lens of the laser crystal is close to a thin lens, according to the theory of transfer matrix we can get that there is a critical hollow point where the resonator changes from stable region to unstable state, then back to stable region. So we can measure the ultrashort thermal focal length of high-power solid-state laser based on this fact. We used this method to measure the ultrashort thermal focal length of a 100W magnitude Nd:YAG laser. The experimental results have shown this is a simple and effective technique.
During design and experiments, multi-diode-laser -module was employed to pump a double AO switched Quasi-CW YAG laser with KTP or LBO crystal as frequency doubler. Thermal lensing effect in laser rod and frequency doubling crystal were both considered. Cavity design with ABCD law and crystal thermal compensation given in detail by numerical calculation. High average power output was achieved.
A solid-state laser source with flat-top wide beam profile was designed and made. The laser source was mainly made up of an Nd:YAG solid-state laser at 1064 nm and a maximum 267 x collimating telescope. A 2 W laser diode (LD) pumped Nd:YAG laser with flat-concave cavity was adopted as the primary laser source at 1064 nm. Then the output laser (1064 nm) was injected into a collimating telescope. We designed three schemes according to spherical wave theory and chose the best one based on our experiments. We found out the spherical aberration (including axial and off-axial points) must be corrected. At last, an output laser beam with 80 mm diameter, 0.4 mrad divergence angle, > 50 mW output power, and ±10% intensity distribution of cross section, was obtained.