The influence of pumping laser pulse on the property of quasi-continuous-wave(QCW)diode-side-pumped Nd:YAG laser is investigated theoretically and experimentally.Under remaining a fixed duty cycle,the average output p...The influence of pumping laser pulse on the property of quasi-continuous-wave(QCW)diode-side-pumped Nd:YAG laser is investigated theoretically and experimentally.Under remaining a fixed duty cycle,the average output power increases,and the corresponding thermal focal length shorten with the increase of the pump pulse duration,which attributes to the decrease of the ratio of pulse buildup time to the pulse duration.At a pump power of 146 W,the laser output power changes from 65.1 W to 81.2 W when the pulse duration is adjusted from 150μs to 1000μs,confirming a significant enhancement of 24.7%.A laser rate equation model incorporating the amplified spontaneous emission is also utilized and numerically solved,and the simulated results agree well with the experimental data.展开更多
We demonstrate an all-solid quasi-continuous-wave （QCW） narrow-band source tunable to sodium D2a line at 589.159 nm. The source is based on sum-frequency mixing between lasers at 1064 nm and 1319 nm in a LBO crystal...We demonstrate an all-solid quasi-continuous-wave （QCW） narrow-band source tunable to sodium D2a line at 589.159 nm. The source is based on sum-frequency mixing between lasers at 1064 nm and 1319 nm in a LBO crystal. The 1064 nm and 1319 nm lasers are produced from two diode side-pumped Nd：YAG master oscillator power amplifier （MOPA） laser systems, respectively. A 33 W output of 589 nm laser is obtained with beam quality factor M^2 = 1.25, frequency stability better than ±0.2 GHz and linewidth less than 0.44 GHz. A prototype 589 nm laser system is assembled, and a sodium laser guided star has been successfully observed in the field test.展开更多
We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse ...We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers.Owing to nonlinear effects,two-or multiphoton absorption dominates over the conventional multistep one-photon process for an optimized γ flash.Moreover,this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser.These low-energy photons act such that the effective cross-section experienced by the γ photons becomes tunable,growing with the intensity I_(0) of the beam.Assuming I_(0)~10^(18) W·cm^(-2) for the photon beam,an effective cross-section as large as 10^(-21)-10^(-28) cm^(2) for the γ photons can be achieved.Thus,with state-of-the-art 10 PW laser facilities,the yields from two-photon absorption can reach 10^(6)-10^(9) isomers per shot for selected states that are separated from their ground state by E2 transitions.Similar yields for transitions with higher multipolarities can be accommodated by multiphoton absorption with additional photons provided.展开更多
In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,th...In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,the average output power of the fundamental laser at 1064 nm reaches as high as 20.98 W at a repetition rate of 50 Hz with a maximum single pulse energy of 419.6 mJ,corresponding to a maximum optical conversion efficiency of 38.8%and a slope efficiency of 41%.展开更多
Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolit...Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolithic nonplanar ring laser is designed. As a result, a laser of hundreds milliwatts cw single frequency output was built up, placed in a magnetic field and pumped by LD. The optical conversion efficiency was more than 15% and the slope efficiency more than 30%. The laser beam had a good quality, with M 2 about 1 2.展开更多
Numerical simulation is described which estimates the performance of thulium sensitized holmium doped CW fluoride fiber laser at 2.04 μm for both core and cladding pumped. This model takes into account the mechanis...Numerical simulation is described which estimates the performance of thulium sensitized holmium doped CW fluoride fiber laser at 2.04 μm for both core and cladding pumped. This model takes into account the mechanisms of cross relaxation and energy transfer to describe the laser operation. A subroutine program for calculating the absorption rate of cladding pumped scheme is included in the model. The losses of signal and pump light along the fiber have been taken into account. The test of cladding pumped scheme program shows good agreement with the experimental result. The experimental results of core pumping Tm Ho doped fiber laser in fluoride host are compared with the present model, and shows a good agreement with calculations. This model also provides data of the optimum parameters for the configuration of the efficient cladding pumped Tm Ho fluoride laser systems.展开更多
This paper presents the cw output characteristics of Nd^(3+):KGd(WO_(4))_(2)(KGW)laser crystal with different NcP+concentration grown in our laboratory.The laser output at 1.067 μm of KGW crystal(3×3×6 mm)w...This paper presents the cw output characteristics of Nd^(3+):KGd(WO_(4))_(2)(KGW)laser crystal with different NcP+concentration grown in our laboratory.The laser output at 1.067 μm of KGW crystal(3×3×6 mm)was obtained to be 68.9 mW and the slope efficiency reached 28.8%when pumped by laser diode of power 305 mW at 807 nm.展开更多
In this paper, according to the temperature and strain distribution obtained by considering the Gaussian pump profile and dependence of physical properties on temperature, we derive an analytical model for refractive ...In this paper, according to the temperature and strain distribution obtained by considering the Gaussian pump profile and dependence of physical properties on temperature, we derive an analytical model for refractive index variations of the diode side-pumped Nd：YAG laser rod. Then we evaluate this model by numerical solution and our maximum relative errors are 5% and 10% for variations caused by thermo–optical and thermo–mechanical effects; respectively. Finally, we present an analytical model for calculating the focal length of the thermal lens and spherical aberration. This model is evaluated by experimental results.展开更多
Based on the effective structure of the self-mixing interference effects,a general model for the self-mixing interference effects in the LD pumped solid-state laser has been established for the first time.The numerica...Based on the effective structure of the self-mixing interference effects,a general model for the self-mixing interference effects in the LD pumped solid-state laser has been established for the first time.The numerical simulation of the self-mixing interference signal has been done,the results show that when the external cavity length is integral times of 1/2,1/3,2/3,1/4,3/4 of the effective cavity length,the intensity of the self-mixing interference signals reach maximum in value.While that of single mode laser is integral times of half of the effective cavity length,the measuring precision of displacement of single mode laser is λ/2.A conclusion can be drawn from the above results that the measuring precision of displacement of multi-mode laser is higher than that of single mode laser.展开更多
Two models of laser diode pumped unidirectional single-frequency ring laser with maximum single frequency output power of 1 W and 780 mW are investigated.The Statistic linewidth of the free-run laser is measured to be...Two models of laser diode pumped unidirectional single-frequency ring laser with maximum single frequency output power of 1 W and 780 mW are investigated.The Statistic linewidth of the free-run laser is measured to be 2.1 kHz within 5μs by using a single mode fiber link.We use the monolithic laser to measure the angular speed of a spinning motor and simulate a linearly frequency modulated continuous-wave ladar system in laboratory.展开更多
Almost all the atoms in the hyperfine sublevel F=4,m_(F)=0("clock level")of cesium ground state have been pumped out by using a laser diode tuned on the Cs-D2 line;and 15.2%population difference(|δoo|)which...Almost all the atoms in the hyperfine sublevel F=4,m_(F)=0("clock level")of cesium ground state have been pumped out by using a laser diode tuned on the Cs-D2 line;and 15.2%population difference(|δoo|)which is more than two times better than what the traditional magnetical selecting state method could provide is found.This experimental result can be applied into building an optically pumped Cs beam frequency standard and better performance will be expected.展开更多
Using a plane–plane resonator composed of silicon carbide mirrors,we achieve for the first time multi-pass amplification of a 46.9 nm laser pumped by capillary discharge.In terms of the temporal characteristics,for a...Using a plane–plane resonator composed of silicon carbide mirrors,we achieve for the first time multi-pass amplification of a 46.9 nm laser pumped by capillary discharge.In terms of the temporal characteristics,for an initial argon pressure of 17 Pa,triple-pass amplification of the laser is obtained at a delay time between the pre-pulse and the main pulse currents of 40s,and quadruple-pass amplification is obtained at a delay time of 50s.The experimental results show that the gain duration of the plasma column is more than 6 ns.In terms of spatial characteristics,the spot of the output laser has a reduced full width at half maximum divergence compared with that from a laser without a resonator.展开更多
A stable wavelength operation Ho:YAG laser dual-pumped by two orthogonally polarized Tm:YLF lasers is reported. Under the cw operation mode, a laser output power of 24 W is measured. The corresponding opticaloptical c...A stable wavelength operation Ho:YAG laser dual-pumped by two orthogonally polarized Tm:YLF lasers is reported. Under the cw operation mode, a laser output power of 24 W is measured. The corresponding opticaloptical conversion efficiency is 44.75% and the slope efficiency is 50.12%. Under the Q-switched operation mode,the output maximum average power is 22.8 W at the re-frequency of 6 kHz. The corresponding optical-optical conversion efficiency and slope efficiency are 42.64% and 48.01%, respectively. The output central wavelength is 2090.73 nm, the linewidth is 0.40 nm, and the beam quality is M^2< 1.6. Moreover, the shift of the output central wavelength is less than 0.01 nm, and the linewidth shift is also less than 0.01 nm.展开更多
A diode-pumped passively Q-switched Nd:YAG/KLu(WO 4 ) 2 (KLW) Raman laser is presented for the first time. As high as 1.89 W average output power is obtained at the pump power of 15.7 W with the pulse repetition frequ...A diode-pumped passively Q-switched Nd:YAG/KLu(WO 4 ) 2 (KLW) Raman laser is presented for the first time. As high as 1.89 W average output power is obtained at the pump power of 15.7 W with the pulse repetition frequency (PRF) of 27.2 kHz, and the corresponding diode-to-Stokes conversion efficiency is 12.0%. The highest pulse energy of 84.0 μJ is obtained. The obtained average output power and pulse energy are much higher than the previously reported results of diode-pumped passively Q-switched Raman lasers.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
We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho：GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.0...We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho：GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.05 W, corresponding to a slope efficiency of 74.6%. The ZGP-OPO laser produces 4.2 ns mid-infrared pulses at a pulse repetition rate of 5 kHz. In addition, we obtain 0.8 um of tunable range for the signal wave and 2.1 um of tunable range for the idler wave.展开更多
An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum i...An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.展开更多
In this paper, we present a study of thermal, average power scaling, change in index of refraction and stress in photonic crystal fiber lasers with different pump schemes: forward pump scheme, backward pump scheme, fo...In this paper, we present a study of thermal, average power scaling, change in index of refraction and stress in photonic crystal fiber lasers with different pump schemes: forward pump scheme, backward pump scheme, forward pump scheme with reflection of 98%, backward pump scheme with reflection of 98% and bi-directional pump scheme. We show that management of thermal effects in fiber lasers will determine the efficiency and success of scaling-up efforts. In addition, we show that the most suitable scheme is the bi-directional.展开更多
The 885 nm direct pumping directly into the^4F_(3/2)emitting level of Nd^(3+)is applied on an Nd:Lu_(0.15)Y_(0.85)VO_4 crystal.The maximum output power of 2.8 W for continuous wave(CW)operation is obtained.For Q-switc...The 885 nm direct pumping directly into the^4F_(3/2)emitting level of Nd^(3+)is applied on an Nd:Lu_(0.15)Y_(0.85)VO_4 crystal.The maximum output power of 2.8 W for continuous wave(CW)operation is obtained.For Q-switched operation,the maximum average output power is 1.2 W with pulse repetition of 23.69 kHz and pulse width of 35 ns at the pump power of 27.9 W.The high-quality fundamental transverse mode can be observed owing to the reduction of thermal effect for Nd:Lu_(0.15)Y_(0.85)VO_4 crystal by 885 nm direct pumping.展开更多
We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber（TDF） laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a ...We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber（TDF） laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a spectral width of 9.7 nm and a repetition rate of 9.33 MHz. The emission wavelength is tunable along with the cavity length detuning in a wide range of 3 mm. The high detuning toleration is beneficial to achieve high temperature and vibration stability in all-fiber configuration lasers.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0402103)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.GJJSTD20180004)the Fund of Technical Institute of Physics and Chemistry,Chinese Academy of Sciences(Grant No.Y8A9021H11)。
文摘The influence of pumping laser pulse on the property of quasi-continuous-wave(QCW)diode-side-pumped Nd:YAG laser is investigated theoretically and experimentally.Under remaining a fixed duty cycle,the average output power increases,and the corresponding thermal focal length shorten with the increase of the pump pulse duration,which attributes to the decrease of the ratio of pulse buildup time to the pulse duration.At a pump power of 146 W,the laser output power changes from 65.1 W to 81.2 W when the pulse duration is adjusted from 150μs to 1000μs,confirming a significant enhancement of 24.7%.A laser rate equation model incorporating the amplified spontaneous emission is also utilized and numerically solved,and the simulated results agree well with the experimental data.
文摘We demonstrate an all-solid quasi-continuous-wave （QCW） narrow-band source tunable to sodium D2a line at 589.159 nm. The source is based on sum-frequency mixing between lasers at 1064 nm and 1319 nm in a LBO crystal. The 1064 nm and 1319 nm lasers are produced from two diode side-pumped Nd：YAG master oscillator power amplifier （MOPA） laser systems, respectively. A 33 W output of 589 nm laser is obtained with beam quality factor M^2 = 1.25, frequency stability better than ±0.2 GHz and linewidth less than 0.44 GHz. A prototype 589 nm laser system is assembled, and a sodium laser guided star has been successfully observed in the field test.
基金supported by the Extreme Light Infrastructure Nuclear Physics(ELI-NP)Phase Ⅱ,a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund—the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)the Romanian Ministry of Research and Innovation:PN23210105(Phase 2,the Program Nucleu),ELI-RO grants Proiectul ELI-RO/RDI_2024_AMAP,ELI-RO_RDI_2024_LaLuThe,ELIRO_RDI_2024_SPARC+4 种基金ELI10/01.10.2020 of the Romanian Governmentthe European Union,the Romanian Governmentthe Health Program,within the project“Medical Applications of High-Power Lasers—Dr.LASER”SMIS Code:326475the IOSIN funds for research infrastructures of national interest.
文摘We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers.Owing to nonlinear effects,two-or multiphoton absorption dominates over the conventional multistep one-photon process for an optimized γ flash.Moreover,this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser.These low-energy photons act such that the effective cross-section experienced by the γ photons becomes tunable,growing with the intensity I_(0) of the beam.Assuming I_(0)~10^(18) W·cm^(-2) for the photon beam,an effective cross-section as large as 10^(-21)-10^(-28) cm^(2) for the γ photons can be achieved.Thus,with state-of-the-art 10 PW laser facilities,the yields from two-photon absorption can reach 10^(6)-10^(9) isomers per shot for selected states that are separated from their ground state by E2 transitions.Similar yields for transitions with higher multipolarities can be accommodated by multiphoton absorption with additional photons provided.
基金supported by the Nanjing University of Posts and Telecommunications Foundation,China(Grant Nos.JUH219002 and JUH219007)the Key R&D Program of Shandong Province,China(Grant No.2021CXGC010202)。
文摘In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,the average output power of the fundamental laser at 1064 nm reaches as high as 20.98 W at a repetition rate of 50 Hz with a maximum single pulse energy of 419.6 mJ,corresponding to a maximum optical conversion efficiency of 38.8%and a slope efficiency of 41%.
基金Fundfor Research on Doctoral Programs in Institutions of Higher Learning
文摘Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolithic nonplanar ring laser is designed. As a result, a laser of hundreds milliwatts cw single frequency output was built up, placed in a magnetic field and pumped by LD. The optical conversion efficiency was more than 15% and the slope efficiency more than 30%. The laser beam had a good quality, with M 2 about 1 2.
文摘Numerical simulation is described which estimates the performance of thulium sensitized holmium doped CW fluoride fiber laser at 2.04 μm for both core and cladding pumped. This model takes into account the mechanisms of cross relaxation and energy transfer to describe the laser operation. A subroutine program for calculating the absorption rate of cladding pumped scheme is included in the model. The losses of signal and pump light along the fiber have been taken into account. The test of cladding pumped scheme program shows good agreement with the experimental result. The experimental results of core pumping Tm Ho doped fiber laser in fluoride host are compared with the present model, and shows a good agreement with calculations. This model also provides data of the optimum parameters for the configuration of the efficient cladding pumped Tm Ho fluoride laser systems.
基金Supported by the National Natural Science Foundation of ChinaFujian Provincial Natural Science Foundation.
文摘This paper presents the cw output characteristics of Nd^(3+):KGd(WO_(4))_(2)(KGW)laser crystal with different NcP+concentration grown in our laboratory.The laser output at 1.067 μm of KGW crystal(3×3×6 mm)was obtained to be 68.9 mW and the slope efficiency reached 28.8%when pumped by laser diode of power 305 mW at 807 nm.
文摘In this paper, according to the temperature and strain distribution obtained by considering the Gaussian pump profile and dependence of physical properties on temperature, we derive an analytical model for refractive index variations of the diode side-pumped Nd：YAG laser rod. Then we evaluate this model by numerical solution and our maximum relative errors are 5% and 10% for variations caused by thermo–optical and thermo–mechanical effects; respectively. Finally, we present an analytical model for calculating the focal length of the thermal lens and spherical aberration. This model is evaluated by experimental results.
文摘Based on the effective structure of the self-mixing interference effects,a general model for the self-mixing interference effects in the LD pumped solid-state laser has been established for the first time.The numerical simulation of the self-mixing interference signal has been done,the results show that when the external cavity length is integral times of 1/2,1/3,2/3,1/4,3/4 of the effective cavity length,the intensity of the self-mixing interference signals reach maximum in value.While that of single mode laser is integral times of half of the effective cavity length,the measuring precision of displacement of single mode laser is λ/2.A conclusion can be drawn from the above results that the measuring precision of displacement of multi-mode laser is higher than that of single mode laser.
文摘Two models of laser diode pumped unidirectional single-frequency ring laser with maximum single frequency output power of 1 W and 780 mW are investigated.The Statistic linewidth of the free-run laser is measured to be 2.1 kHz within 5μs by using a single mode fiber link.We use the monolithic laser to measure the angular speed of a spinning motor and simulate a linearly frequency modulated continuous-wave ladar system in laboratory.
文摘Almost all the atoms in the hyperfine sublevel F=4,m_(F)=0("clock level")of cesium ground state have been pumped out by using a laser diode tuned on the Cs-D2 line;and 15.2%population difference(|δoo|)which is more than two times better than what the traditional magnetical selecting state method could provide is found.This experimental result can be applied into building an optically pumped Cs beam frequency standard and better performance will be expected.
基金funded by the National Natural Science Foundation of China(Grant Nos.61875045 and 62005066).
文摘Using a plane–plane resonator composed of silicon carbide mirrors,we achieve for the first time multi-pass amplification of a 46.9 nm laser pumped by capillary discharge.In terms of the temporal characteristics,for an initial argon pressure of 17 Pa,triple-pass amplification of the laser is obtained at a delay time between the pre-pulse and the main pulse currents of 40s,and quadruple-pass amplification is obtained at a delay time of 50s.The experimental results show that the gain duration of the plasma column is more than 6 ns.In terms of spatial characteristics,the spot of the output laser has a reduced full width at half maximum divergence compared with that from a laser without a resonator.
基金Supported by the Cooperation Foundation of Changchun Science and Technology Bureau under Grant No 17DY027the Foundation of Education Department of Jilin Province under Grant No JJKH20181105KJthe Foundation of Jilin Province Science and Technology Department under Grant No 20180101033JC
文摘A stable wavelength operation Ho:YAG laser dual-pumped by two orthogonally polarized Tm:YLF lasers is reported. Under the cw operation mode, a laser output power of 24 W is measured. The corresponding opticaloptical conversion efficiency is 44.75% and the slope efficiency is 50.12%. Under the Q-switched operation mode,the output maximum average power is 22.8 W at the re-frequency of 6 kHz. The corresponding optical-optical conversion efficiency and slope efficiency are 42.64% and 48.01%, respectively. The output central wavelength is 2090.73 nm, the linewidth is 0.40 nm, and the beam quality is M^2< 1.6. Moreover, the shift of the output central wavelength is less than 0.01 nm, and the linewidth shift is also less than 0.01 nm.
基金supported by the National Natural Science Foundation of China (No.11174185)the Natural Science Foundation of Shandong Province (No.2009ZRB019OE)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China (No.20100131110064)the Science and Technology Development Program of Jinan in Shandong Province (No.200906009)
文摘A diode-pumped passively Q-switched Nd:YAG/KLu(WO 4 ) 2 (KLW) Raman laser is presented for the first time. As high as 1.89 W average output power is obtained at the pump power of 15.7 W with the pulse repetition frequency (PRF) of 27.2 kHz, and the corresponding diode-to-Stokes conversion efficiency is 12.0%. The highest pulse energy of 84.0 μJ is obtained. The obtained average output power and pulse energy are much higher than the previously reported results of diode-pumped passively Q-switched Raman lasers.
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.
基金Supported by the National Natural Science Foundation of China under Grant No 51572053
文摘We demonstrate a middle infrared ZnGeP_2 optical parametric oscillator pumped by the Q-switched Ho：GdVO_4 laser. When the incident Ho pump power is 4.12 W, the maximum average output power of the ZGP-OPO laser is 2.05 W, corresponding to a slope efficiency of 74.6%. The ZGP-OPO laser produces 4.2 ns mid-infrared pulses at a pulse repetition rate of 5 kHz. In addition, we obtain 0.8 um of tunable range for the signal wave and 2.1 um of tunable range for the idler wave.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61308009 and 61405047the China Postdoctoral Science Foundation Funded Project under Grant Nos 2013M540288 and 2015M570290+2 种基金the Fundamental Research Funds for the Central Universities Grant under Grant Nos HIT.NSRIF.2014044 and HIT.NSRIF.2015042the Science Fund for Outstanding Youths of Heilongjiang Province under Grant No JQ201310the Heilongjiang Postdoctoral Science Foundation Funded Project under Grant No LBH-Z14085
文摘An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.
文摘In this paper, we present a study of thermal, average power scaling, change in index of refraction and stress in photonic crystal fiber lasers with different pump schemes: forward pump scheme, backward pump scheme, forward pump scheme with reflection of 98%, backward pump scheme with reflection of 98% and bi-directional pump scheme. We show that management of thermal effects in fiber lasers will determine the efficiency and success of scaling-up efforts. In addition, we show that the most suitable scheme is the bi-directional.
基金supported by the Natural Science Foundation of Heilongjiang Province of China(No.F201335)the Science and Technology Research Projects of Heilongjiang Province Education Department(No.12531751)
文摘The 885 nm direct pumping directly into the^4F_(3/2)emitting level of Nd^(3+)is applied on an Nd:Lu_(0.15)Y_(0.85)VO_4 crystal.The maximum output power of 2.8 W for continuous wave(CW)operation is obtained.For Q-switched operation,the maximum average output power is 1.2 W with pulse repetition of 23.69 kHz and pulse width of 35 ns at the pump power of 27.9 W.The high-quality fundamental transverse mode can be observed owing to the reduction of thermal effect for Nd:Lu_(0.15)Y_(0.85)VO_4 crystal by 885 nm direct pumping.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61675188 and 61875052the Open Fund of Key Laboratory Pulse Power Laser Technology of China under Grant No SKL2016KF03
文摘We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber（TDF） laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a spectral width of 9.7 nm and a repetition rate of 9.33 MHz. The emission wavelength is tunable along with the cavity length detuning in a wide range of 3 mm. The high detuning toleration is beneficial to achieve high temperature and vibration stability in all-fiber configuration lasers.
