A compact high power diode-pumped passively mode-locked Nd:YVO_4 laser with high repetition rate is realized.Using an Nd:YVO_4 crystal and a semiconductor saturable absorber mirror(SESAM) in the oscillator, the picose...A compact high power diode-pumped passively mode-locked Nd:YVO_4 laser with high repetition rate is realized.Using an Nd:YVO_4 crystal and a semiconductor saturable absorber mirror(SESAM) in the oscillator, the picosecond pulse output with an average power of 1.38 W, a repetition rate of 3.24 GHz, and a pulse duration of 11.4 ps is achieved. After one stage of amplification, the final output power reaches 11.34 W, corresponding to a total optical-to-optical efficiency of about 32%. The root mean square(RMS) value of power fluctuation is demonstrated to be less than 0.6% in 24 hours,showing a superior stability with the compact configuration.展开更多
A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-sw...A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.展开更多
We report a low-noise continous-wave single-frequency Nd:YVO4 laser at 1.06μm directly pumped by an 880-nm laser diode.A maximum output power of 22 W is achieved with an optical-to-optical conversion efficiency of 46...We report a low-noise continous-wave single-frequency Nd:YVO4 laser at 1.06μm directly pumped by an 880-nm laser diode.A maximum output power of 22 W is achieved with an optical-to-optical conversion efficiency of 46.3%.The stability of the output is better than ±0.7% in the given four hours.The output beam is almost diffraction-Iimited with a measured beam quality of M^(2)_(x) =1.05 and M^(2)_(y) =1.02.The intensity noise and the phase noise of the laser reach the shot-noise limit at an analysis frequency of 5 MHz.展开更多
A compact, efficient and high-power laser diode （LD） single-end-pumped Nd：YVO4 laser with continuous-wave emission at 1342 nm is reported. With a single crystal single-end-pumped by fibre-coupled LD array, an outpu...A compact, efficient and high-power laser diode （LD） single-end-pumped Nd：YVO4 laser with continuous-wave emission at 1342 nm is reported. With a single crystal single-end-pumped by fibre-coupled LD array, an output power of 7.36W is obtained from the laser cavity of concave-convex shape, corresponding to an optical-to-optical efficiency of 32.8%. The laser is operated in TEM00 mode with small rms amplitude noise of 0.3%. The influences of the Nd concentration, transmissivity of the output mirror and the cavity length on the output power have been studied experimentally.展开更多
The thermal effect and the heat generation in diode-end-pumped continuous-wave 914-nm Nd：YVO4 lasers are investigated in detail. A theoretical model of a diode end-pumped solid-state laser is constructed to analyse t...The thermal effect and the heat generation in diode-end-pumped continuous-wave 914-nm Nd：YVO4 lasers are investigated in detail. A theoretical model of a diode end-pumped solid-state laser is constructed to analyse the influence of fractional thermal loading on the thermal effect in the Nd：YVO4 laser based on finite element analysis. The thermal focal lengths and the end-surface deformations of laser rods in Nd：YVO4 quasi-three-level and four-level lasers are measured and compared with the results obtained by ordinary interferometry for the demonstration of higher thermal loading in 914-nm laser. Finally the fractional thermal loading in the Nd：YVO4 quasi-three-level laser is calculated by matching the experimental and the simulated end deformations.展开更多
An efficient 1064-nm Nd：YVO_4laser in-band pumped by a wavelength-locked laser diode（LD） at 913.9 nm was demonstrated. The maximum continuous wave（CW） output power of 23.4 W at 1064 nm was realized with the incid...An efficient 1064-nm Nd：YVO_4laser in-band pumped by a wavelength-locked laser diode（LD） at 913.9 nm was demonstrated. The maximum continuous wave（CW） output power of 23.4 W at 1064 nm was realized with the incident pump power of 40 W, corresponding to a total optical-to-optical efficiency of 58.5%. This is to the best of our knowledge the highest total optical-to-optical efficiency and output power of Nd：YVO_4laser in-band pumped by a 913.9-nm laser diode.The Q-switched operation of this laser was also investigated. Through a contrast experiment of pumping at 808 nm, the experimental results showed that an Nd：YVO_4laser in-band pumped by a wavelength-locked LD at 913.9 nm had excellent pulse stability and beam quality for high repetition rate Q-switching operation.展开更多
We reported an efficient diode pumped Nd∶YVO4 1 064 nm laser passively mode-locked and Q-switched by a semiconductor saturable absorber mirror(SESAM). At the incident pump power of 7.5 W, 2.81 W average output power ...We reported an efficient diode pumped Nd∶YVO4 1 064 nm laser passively mode-locked and Q-switched by a semiconductor saturable absorber mirror(SESAM). At the incident pump power of 7.5 W, 2.81 W average output power was obtained during stable CW mode locking with a repetition rate of 111 MHz. The optical conversion efficiency was 37.5%, and the slope efficiency was 39%. So far as we know, this is the highest optical-optical conversion efficiency with a SESAM at home.展开更多
A passively Q-switched Nd：YVO4 laser at 1064 nm is demonstrated based on a gold nanotriangle saturable absorber（GNT SA）.Under a pump power of 3.82 W,the maximum average output power of 218mW is achieved,correspondi...A passively Q-switched Nd：YVO4 laser at 1064 nm is demonstrated based on a gold nanotriangle saturable absorber（GNT SA）.Under a pump power of 3.82 W,the maximum average output power of 218mW is achieved,corresponding to a slope efficiency of 12.9%.The minimum pulse width is 165ns and the maximum pulse repetition rate is 300kHz at the pump power of 3.48 W.Our results prove that the GNT SA is a promising saturable absorber for near-infrared lasers.展开更多
A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q...A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q-switched Nd:YVO4 laser is demonstrated. One reflecting Bragg gratings is used as the output coupler for mode selection. By inserting those BP-SA solutions in the laser cavity, the maximum single longitude mode, Q-switched output powers of 126mW at 692.5 kHz and 149mW at 630.3 kHz are achieved at the pump power of 8.0 W, corresponding to the pulse durations of 144 ns and 196 ns, respectively. Moreover, longitudinal-mode characteristics of Q-switched output laser in different optical cavity lengths based on two-kind BP-SA solution concentrations are investigated. Our results show that BP-SA could also be developed as an effective SA for the Q-switched, single longitudinal mode pulse laser.展开更多
A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved....A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.展开更多
We presented a novel orthogonally linearly polarized Nd：YVO4 laser. Two pieces of a-cut grown-together composite YVO4/Nd：YVO4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogona...We presented a novel orthogonally linearly polarized Nd：YVO4 laser. Two pieces of a-cut grown-together composite YVO4/Nd：YVO4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally. The polarization and power performance of the orthogonally polarized laser were investigated. A 26.2-W orthogonally linearly polarized laser was obtained. The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling. The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser. We also adjusted the crystals with their c-axis parallele to each other, and a 40.7-W linearly polarized TEM00 laser was obtained, and the beam quality factors were Mx^2 = 1.37 and My^2 = 1.25.展开更多
A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achiev...A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achieved by double-passing the first amplifier stage and single-passing the second stage with an optical efficiency of 29% while working at a frequency of 1kHz and pulse width of 200 μs.展开更多
A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-seg...A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-segmented（Nd：YAG ＋ Nd：YVO4） and conventional composite（Nd：YAG ＋ Nd：YAG） crystals to demonstrate the feasibility of spectral line matching for output power scale-up in end-pumped lasers. A maximum continuous-wave output power of 79.2 W is reported at 1064 nm, with Mx2= 4.82, My2= 5.48, and a pumping power of 136 W in the multi-segmented crystals（Nd：YAG ＋ Nd：YVO4）. Compared to conventional composite crystals（Nd：YAG ＋ Nd：YAG）, the optical-optical conversion efficiency of multi-segmented crystals（Nd：YAG ＋ Nd：YVO4） from 808 nm to 1064 nm is enhanced from 30% to 58.8%,while the laser output sensitivity as affected by the diode-laser temperature is reduced from 55% to 9%.展开更多
We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corre...We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corresponding to a pump extraction efficiency of 16.1%(19.5% for the second stage) and peak power of ~1.5 MW.The beam quality factors at maximum output power are measured to be Mx2= 1.56 and My2= 1.48. We introduce an analytical model to estimate gain and beam quality after amplification. This model focuses on the influence of ratio of seed spot radius to pump spot radius when designing an amplifier. Moreover, our experiments reveal that the re-imaging system in the double-pass configuration can be used to enhance the beam quality.展开更多
A continuous-wave(CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd:YVO4 and using LBO as the intra-cavity SHG crystal.With the optimization of...A continuous-wave(CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd:YVO4 and using LBO as the intra-cavity SHG crystal.With the optimization of laser cavity and crystal parameters,the laser operates at a very high efficiency.When the pumping power is about 31 W,the output at 457 nm reaches 4.2 W,and the optical to optical conversion efficiency is about 13.5% accordingly.The stability of the output power is better than 1.2% for 8 h continuously working.展开更多
Different material-doped Raman fiber lasers with very high efficiency operating in continuous-wave are presented.With 1 W Nd∶YVO 4 laser pumping at wavelength of 1 342 nm, single mode output power of above 500 mW (op...Different material-doped Raman fiber lasers with very high efficiency operating in continuous-wave are presented.With 1 W Nd∶YVO 4 laser pumping at wavelength of 1 342 nm, single mode output power of above 500 mW (optical-to-optical conversion efficiency of 50%) is simulated in the range of 1 400-1 500 nm.Using high-germanium,high-phosphate and high-borate silicate fibers as the gain medium,laser output at wavelengths of 1 420,1 450,1 480 and 1 495 nm can be achieved with different geometries,which are just as pumping C-band and L-band distributed Raman fiber amplifiers.展开更多
Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high efficiency for laser range finding and warning receiver applications as well as day and night military laser designati...Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high efficiency for laser range finding and warning receiver applications as well as day and night military laser designation systems. In this paper we presents theoretical calculations using Advanced Dynamics Professional LASCAD software and experimental studies for a high power pigtailed fiber diode laser module of 8 W operating at 808 nm with a specially designed high efficiency cooling system, end pumped high-efficiency Nd:YVO4 laser of 3 × 3 × 10 mm rod and overall cavity length of 44 mm. To the best of our knowledge a self Q-switching effects was generated in Nd:YVO4 laser by changing the cavity dimensions and the position of the intracavity KTP crystal at certain regime of operation for the first time, in which the cavity length is reduced to be 30 mm and the distance between Nd:YVO4 rod and KTP crystal is only 1mm. Self Q-switched laser pulse at 532 nm with high peak power of 96 W, pulse width of 88 ns at FWHM and repetition rate of 400 kHz was achieved. Experimental studies of a passive Q-switched Nd:YVO4 laser using Cr:YAG crystal with three different transmissions of 30%, 40% and 70% were investigated. Passive Q-switched laser pulse at 1064 nm and narrow line width of less than 1.5 nm with highest peak power of nearly 18 kW, short pulse width of less than 4 ns at FWHM and higher repetition rate of 45 kHz using Cr:YAG with transmission of 30% was achieved for the first time.展开更多
基金Project supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB16030200)the National Natural Science Foundation of China(Grant Nos.11774410 and 61575217)+1 种基金the National Key Scientific Instruments Development Program of China(Grant No.2012YQ120047)the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Grant No.KJZD-EW-L11-03)
文摘A compact high power diode-pumped passively mode-locked Nd:YVO_4 laser with high repetition rate is realized.Using an Nd:YVO_4 crystal and a semiconductor saturable absorber mirror(SESAM) in the oscillator, the picosecond pulse output with an average power of 1.38 W, a repetition rate of 3.24 GHz, and a pulse duration of 11.4 ps is achieved. After one stage of amplification, the final output power reaches 11.34 W, corresponding to a total optical-to-optical efficiency of about 32%. The root mean square(RMS) value of power fluctuation is demonstrated to be less than 0.6% in 24 hours,showing a superior stability with the compact configuration.
基金Supported by the Science and Technology Department Project of Jilin Province under Grant Nos 2010PT and 20100355.
文摘A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.
基金Supported by the National Natural Science Foundation of China under Grant No 60878003the National Basic Research Program of China(2010CB923101)the National High-tech R&D Program of China(2011AA030203).
文摘We report a low-noise continous-wave single-frequency Nd:YVO4 laser at 1.06μm directly pumped by an 880-nm laser diode.A maximum output power of 22 W is achieved with an optical-to-optical conversion efficiency of 46.3%.The stability of the output is better than ±0.7% in the given four hours.The output beam is almost diffraction-Iimited with a measured beam quality of M^(2)_(x) =1.05 and M^(2)_(y) =1.02.The intensity noise and the phase noise of the laser reach the shot-noise limit at an analysis frequency of 5 MHz.
文摘A compact, efficient and high-power laser diode （LD） single-end-pumped Nd：YVO4 laser with continuous-wave emission at 1342 nm is reported. With a single crystal single-end-pumped by fibre-coupled LD array, an output power of 7.36W is obtained from the laser cavity of concave-convex shape, corresponding to an optical-to-optical efficiency of 32.8%. The laser is operated in TEM00 mode with small rms amplitude noise of 0.3%. The influences of the Nd concentration, transmissivity of the output mirror and the cavity length on the output power have been studied experimentally.
基金supported by the National Natural Science Foundation of China (Grant No.60978016)the Technological Project of Heilongjiang Province,China (Grant No.GC06A116)the Fundamental Research Funds for the Central Universities,China (Grant No.HIT.NSRIF.201165)
文摘The thermal effect and the heat generation in diode-end-pumped continuous-wave 914-nm Nd：YVO4 lasers are investigated in detail. A theoretical model of a diode end-pumped solid-state laser is constructed to analyse the influence of fractional thermal loading on the thermal effect in the Nd：YVO4 laser based on finite element analysis. The thermal focal lengths and the end-surface deformations of laser rods in Nd：YVO4 quasi-three-level and four-level lasers are measured and compared with the results obtained by ordinary interferometry for the demonstration of higher thermal loading in 914-nm laser. Finally the fractional thermal loading in the Nd：YVO4 quasi-three-level laser is calculated by matching the experimental and the simulated end deformations.
基金Project supported by Tianjin City High School Science&Technology Fund Planning Project(Grant No.20140703)
文摘An efficient 1064-nm Nd：YVO_4laser in-band pumped by a wavelength-locked laser diode（LD） at 913.9 nm was demonstrated. The maximum continuous wave（CW） output power of 23.4 W at 1064 nm was realized with the incident pump power of 40 W, corresponding to a total optical-to-optical efficiency of 58.5%. This is to the best of our knowledge the highest total optical-to-optical efficiency and output power of Nd：YVO_4laser in-band pumped by a 913.9-nm laser diode.The Q-switched operation of this laser was also investigated. Through a contrast experiment of pumping at 808 nm, the experimental results showed that an Nd：YVO_4laser in-band pumped by a wavelength-locked LD at 913.9 nm had excellent pulse stability and beam quality for high repetition rate Q-switching operation.
基金National Natural Science Foundation of China (50602037) Award Fund of Shandong Excellent Young Scientists(2005BS04001)
文摘We reported an efficient diode pumped Nd∶YVO4 1 064 nm laser passively mode-locked and Q-switched by a semiconductor saturable absorber mirror(SESAM). At the incident pump power of 7.5 W, 2.81 W average output power was obtained during stable CW mode locking with a repetition rate of 111 MHz. The optical conversion efficiency was 37.5%, and the slope efficiency was 39%. So far as we know, this is the highest optical-optical conversion efficiency with a SESAM at home.
基金Supported by the National Natural Science Foundation of China under Grant No 61475086the Natural Science Foundation of Shandong Province under Grant Nos ZR2015FM018 and ZR2014FM028
文摘A passively Q-switched Nd：YVO4 laser at 1064 nm is demonstrated based on a gold nanotriangle saturable absorber（GNT SA）.Under a pump power of 3.82 W,the maximum average output power of 218mW is achieved,corresponding to a slope efficiency of 12.9%.The minimum pulse width is 165ns and the maximum pulse repetition rate is 300kHz at the pump power of 3.48 W.Our results prove that the GNT SA is a promising saturable absorber for near-infrared lasers.
基金Supported by West Young Scholar Foundation of the Chinese Academy of Sciences under Grant No XAB2015B27
文摘A black phosphorus (BP) saturable absorber (SA) solution with different concentrations (1.0 and 0.5 mg/ml) is fabricated with the liquid-phase exfoliation method. By using the BP-SA, a compact diode-pumped passively Q-switched Nd:YVO4 laser is demonstrated. One reflecting Bragg gratings is used as the output coupler for mode selection. By inserting those BP-SA solutions in the laser cavity, the maximum single longitude mode, Q-switched output powers of 126mW at 692.5 kHz and 149mW at 630.3 kHz are achieved at the pump power of 8.0 W, corresponding to the pulse durations of 144 ns and 196 ns, respectively. Moreover, longitudinal-mode characteristics of Q-switched output laser in different optical cavity lengths based on two-kind BP-SA solution concentrations are investigated. Our results show that BP-SA could also be developed as an effective SA for the Q-switched, single longitudinal mode pulse laser.
基金Supported by the Foundation of the State Key Laboratory of Crystal Material of Shandong University under Grant No KF1101the Foundation of Shandong University under Grant No 1170072613176+2 种基金the National Natural Science Foundation of China under Grant Nos 11004122 and 11204160the Special Grade of China Postdoctoral Science Foundation under Grant No 201104627the Independent Innovation Foundation of Shandong University under Grant No 2011GN058
文摘A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50721004 and 60978032)
文摘We presented a novel orthogonally linearly polarized Nd：YVO4 laser. Two pieces of a-cut grown-together composite YVO4/Nd：YVO4 crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally. The polarization and power performance of the orthogonally polarized laser were investigated. A 26.2-W orthogonally linearly polarized laser was obtained. The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling. The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser. We also adjusted the crystals with their c-axis parallele to each other, and a 40.7-W linearly polarized TEM00 laser was obtained, and the beam quality factors were Mx^2 = 1.37 and My^2 = 1.25.
文摘A high power Nd：YAG end-pumped slab amplifier chain with a Nd：YVO4 innoslab laser as the master oscillator is demonstrated. A chain output power of 5210 W with beam quality of 4 times the diffraction limit is achieved by double-passing the first amplifier stage and single-passing the second stage with an optical efficiency of 29% while working at a frequency of 1kHz and pulse width of 200 μs.
基金Project supported by the National Defense Pre-Research Foundation of China(Grant No.9140A020105)
文摘A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-segmented（Nd：YAG ＋ Nd：YVO4） and conventional composite（Nd：YAG ＋ Nd：YAG） crystals to demonstrate the feasibility of spectral line matching for output power scale-up in end-pumped lasers. A maximum continuous-wave output power of 79.2 W is reported at 1064 nm, with Mx2= 4.82, My2= 5.48, and a pumping power of 136 W in the multi-segmented crystals（Nd：YAG ＋ Nd：YVO4）. Compared to conventional composite crystals（Nd：YAG ＋ Nd：YAG）, the optical-optical conversion efficiency of multi-segmented crystals（Nd：YAG ＋ Nd：YVO4） from 808 nm to 1064 nm is enhanced from 30% to 58.8%,while the laser output sensitivity as affected by the diode-laser temperature is reduced from 55% to 9%.
基金Supported by the Natural Science Foundation of Guangdong Province under Grant Nos 2017A030310305 and 2018A030310092the Young Teachers Training Program of the Fundamental Research Funds for Sun Yat-sen University under Grant No20174500031610017
文摘We develop a two-stage end-pumped Nd:YVO4 amplifier seeded by a passively Q-switched microchip laser. An average output power of 13.5 W with repetition rate up to 7 kHz and pulse duration of ~1.24 ns is obtained,corresponding to a pump extraction efficiency of 16.1%(19.5% for the second stage) and peak power of ~1.5 MW.The beam quality factors at maximum output power are measured to be Mx2= 1.56 and My2= 1.48. We introduce an analytical model to estimate gain and beam quality after amplification. This model focuses on the influence of ratio of seed spot radius to pump spot radius when designing an amplifier. Moreover, our experiments reveal that the re-imaging system in the double-pass configuration can be used to enhance the beam quality.
文摘A continuous-wave(CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd:YVO4 and using LBO as the intra-cavity SHG crystal.With the optimization of laser cavity and crystal parameters,the laser operates at a very high efficiency.When the pumping power is about 31 W,the output at 457 nm reaches 4.2 W,and the optical to optical conversion efficiency is about 13.5% accordingly.The stability of the output power is better than 1.2% for 8 h continuously working.
文摘Different material-doped Raman fiber lasers with very high efficiency operating in continuous-wave are presented.With 1 W Nd∶YVO 4 laser pumping at wavelength of 1 342 nm, single mode output power of above 500 mW (optical-to-optical conversion efficiency of 50%) is simulated in the range of 1 400-1 500 nm.Using high-germanium,high-phosphate and high-borate silicate fibers as the gain medium,laser output at wavelengths of 1 420,1 450,1 480 and 1 495 nm can be achieved with different geometries,which are just as pumping C-band and L-band distributed Raman fiber amplifiers.
文摘Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high efficiency for laser range finding and warning receiver applications as well as day and night military laser designation systems. In this paper we presents theoretical calculations using Advanced Dynamics Professional LASCAD software and experimental studies for a high power pigtailed fiber diode laser module of 8 W operating at 808 nm with a specially designed high efficiency cooling system, end pumped high-efficiency Nd:YVO4 laser of 3 × 3 × 10 mm rod and overall cavity length of 44 mm. To the best of our knowledge a self Q-switching effects was generated in Nd:YVO4 laser by changing the cavity dimensions and the position of the intracavity KTP crystal at certain regime of operation for the first time, in which the cavity length is reduced to be 30 mm and the distance between Nd:YVO4 rod and KTP crystal is only 1mm. Self Q-switched laser pulse at 532 nm with high peak power of 96 W, pulse width of 88 ns at FWHM and repetition rate of 400 kHz was achieved. Experimental studies of a passive Q-switched Nd:YVO4 laser using Cr:YAG crystal with three different transmissions of 30%, 40% and 70% were investigated. Passive Q-switched laser pulse at 1064 nm and narrow line width of less than 1.5 nm with highest peak power of nearly 18 kW, short pulse width of less than 4 ns at FWHM and higher repetition rate of 45 kHz using Cr:YAG with transmission of 30% was achieved for the first time.
