增益调制高重频脉冲光纤激光器实验研究

采用脉冲泵浦方案,研制出了基于增益调制技术的全光纤结构高重频脉冲激光器。采用电路直接调制的激光二极管作为泵浦源,双包层光纤作为增益介质,构造了光纤光栅选模的线形腔结构。实验中通过调整泵浦光脉冲宽度和光纤激光器谐振腔长度,得到了稳定的高重频脉冲。在100kHz重复频率下,采用21W的峰值泵浦功率和2.5μs的泵浦脉冲宽度,获得了1.06μm波长,脉冲宽度247ns的稳定脉冲激光输出。脉冲峰值功率一致性好,平均功率长期功率稳定性为2%。观察并分析了由于纵模拍频在脉冲包络上产生的次脉冲特性。通过一级放大实现89.6 W输出。     

Diode-pumped high-repetition-rate acousto-optically Q-switched Nd:YVO<Subscript>4</Subscript> laser operating at 914 nm

A diode-pumped high-repetition-rate acousto-optically (A-O) Q-switched Nd:YVO₄ laser operating at 914 nm was reported in this paper. Employing a compact linear laser cavity, at an operating repetition rate of 10 kHz, a maximum average output power of 2.2 W 914 nm laser was obtained at an incident pump power of 45.3 W, corresponding to an optical conversion efficiency of 4.9% and a slope efficiency of 8.8%. Minimum pulse width of 24 ns and maximum peak power of 8.0 kW of 914 nm laser was also achieved at an incident pump power of 40.8 W. To the best of our knowledge, this is the highest peak power of 914 nm laser at 10 kHz by far. Moreover, the highest operating repetition rate of pulsed 914 nm can even reach 100 kHz.     

High repetition rate,high peak power acousto-optical Q-switched 946 nm Nd:YAG laser

A diode-end-pumped high repetition rate, high peak power acousto-optical (AO) Q-switched 946 nm Nd:YAG laser was demonstrated in this paper. In our experiments, a 20 mm miniature acousto-optical Q-switch was employed in a 45 mm linear laser cavity for generating the short laser pulse. At a repetition rate of 10 kHz, a maximum average output power of 2.9 W was achieved with a pulse width of 24.4 ns, giving a peak power of 11.9 kW. To the best of our knowledge, this is the highest peak power 946 nm Nd:YAG laser at high repetition rate operation. Moreover, pulse train with good stability was also obtained at the repetition rate of 50 kHz. At an incident pump power of 22.3 W, up to an average output power of 3.5 W pulsed 946 nm laser was generated at 50 kHz with a pulse width of 69 ns, corresponding to an optical conversion efficiency of 15.7% and an average slope efficiency of 24.1%, respectively.     

LD-pumped actively Q-switched Yb:YAG laser with an acoustic-optical modulator

We have investigated an acoustic-optical Q-switched Yb:YAG laser end-pumped by a fiber-coupled laser diode. At room temperature, the 1030-nm wavelength pulsed output is realized. When the incident power was 11.3 W, a maximum average output power of 1.034 W is achieved at the repetition frequency of 20 kHz, and this corresponds to an optical conversion efficiency of 9.1%. The shortest laser pulse width of 37.4 ns was observed at the repetition frequency of 5 kHz, when the incident power was 11.3 W. The highest peak power 6.79 kW was achieved at the repetition frequency of 1.12 kHz, when the incident power was 8.7 W. The highest single-pulse energy of 319.67 μJ was achieved at the repetition frequency of 1.12 kHz, when the incident power was 10.14 W.     

Nd:YVO4声光调Q腔内倍频457 nm蓝光激光器

脉冲蓝光激光器在水下探测、水下通信和遥感方面有着重要的应用前景。根据高斯光束传输的ABCD矩阵,设计了对热效应不灵敏的Z型谐振腔。利用808 nm激光二极管(LD)端面抽运Nd:YVO4晶棒,在室温下实现了4F3/2→4I9/2准三能级激光谱线跃迁。通过声光调Q和LBO腔内倍频,获得了稳定的高重复频率、高峰值功率457 nm蓝光激光输出。当抽运功率为30 W时,在重复频率为10 kHz下,获得最大单脉冲能量为56 μJ ,脉冲宽度为217 ns,峰值功率达258 W; 在重复频率为20 kHz下,获得最大平均功率为760 mW,脉冲宽度为261 ns,峰值功率为146 W。在最大平均输出功率下测量了脉冲457 nm蓝光激光器的功率稳定性,20 min之内其最大不稳定度小于2%。     

50.2W high stability and high compact all-solid-state green laser with extra-cavity frequency-doubling at 500 Hz

A 50.2W high pulse energy green laser system at 532 nm was demonstrated by extra-cavity second-harmonic generation (SHG). The fundamental laser was based on laser diode (LD) side-pumped MOPA Q-switched technology, producing 79W of average power at the repetition rate of 500 Hz, while the pulse width was 6 ns. Type-II angle phasematched KTiOPO₄ (KTP) crystal was used as the nonlinear crystal. The 50.2W average power of 532 nm laser was obtained with the divergence angle less than 0.6 mrad and the corresponding peak power of 16.7MW. The optical frequency conversion efficiency from fundamental to green laser was up to 63.5%. The measured output power fluctuation was less than 0.38% in one hour operation.     

LD-pumped passively Q-switched Nd:YVO4 infrared and green lasers

A laser diode directly end-pumped, passively Q-switched Nd:YVO₄/Cr:YAG laser is presented in this paper. With 600 mW incident pump laser, Q-switched 1064 nm laser with an average power of 138 mW, pulse width of 19.8 ns, repetition rate of 170.1 kHz and peak power of 40.96 W is obtained. When a KTP crystal was inserted into the cavity, Q-switched 532 nm laser with an average power of 56 mW, pulse width of 28.4 ns, repetition rate of 118.2 kHz and peak power of 16.7 W is obtained at last.     

LD泵浦Cr∶YAG被动调Q 556nm黄光激光器

通过对谐振腔镜镀制合理的激光薄膜，成功实现了LD泵浦Nd∶YAG 1.111 μm激光谱线的运转.利用LBO腔内倍频Nd∶YAG/Cr∶YAG结构获得了高重复频率被动调Q556 nm全固态黄光激光器，在注入泵浦功率为1.6 W时，得到平均功率51 mW，脉冲宽度48 ns,重复频率8.9 kHz,峰值功率高达119 W的脉冲黄光输出.     

10-W-level diode-pumped compact 2.78 microm ZBLAN fiber laser

We report on >9W transverse-fundamental-mode CW output near 3 mum from a 4m heavily erbium-doped ZBLAN double-clad fiber laser pumped by a collimated 100 W 975 nm laser diode array. The pump threshold of the fiber laser was about 1W, and the slope efficiency was 21.3%. The peak wavelength of free running was about 2708 nm at low pump power and moved to around 2785 nm at high pump power. Output of 9W was obtained when the launched pump power was 42.8W. The output, however, fluctuated intensively like a pulsed laser, and the operation broke down with optical damage of the pumping end facet when the pump was increased beyond 42.8 W. Therefore, alleviation of the operation fluctuation, heat management, and strengthening the pumping fiber are crucial considerations for the stable operation of 10-W-level mid-IR ZBLAN fiber lasers.     

940nm波长高功率线阵二极管激光器封装研究

 对940nm波长高功率线阵二极管激光器的封装结构进行了重新设计，并在此基础上开展了芯片的封装实验。封装出的线阵二极管激光器，在连续工作时输出激光功率达40W，在准连续工作时（占空比0.5%），输出峰值功率可达100W。     

二极管泵浦自启动附加脉冲锁模Nd:YLF激光器

实现了激光二极管泵浦Nd:YLF激光器的自启动附加脉冲锁模,工作波长1053um,得到2.8ps的超短脉冲,重复频率130MHz,有效输出功率70mW.     

1318.8 nm/1338.2 nm simultaneous dual-wavelength Q-switched Nd:YAG laser

A diode-side-pumped simultaneous dual-wavelength Q-switched Nd:YAG laser around 1.3 μm is demonstrated. With the pumping power of 480 W, a peak power of 43 kW was obtained at the repetition rate of 5 kHz. The maximum average output power is up to 43 W with the slope efficiency of 20.5%, and the pulse duration is 200 ns. This dual-wavelength Q-switched laser with high peak power has a balanceable and stable proportion of dual-wavelength output. PACS 42.55.Xi; 42.60.Gd     

可调脉冲宽度的调Q掺铥双包层光纤激光器

在激光器输出平均功率一定的情况下,峰值功率主要取决于调制频率和脉冲宽度。这使得脉冲宽度的调节具有一定的实际应用价值。对调Q掺铥双包层光纤激光器进行研究,首先确定了激光器的最佳输出透过率,在65%最佳透过率时,得到2 m激光的输出功率3.9 W,斜率效率为31%。外接一个信号发生器,信号门宽从12 s变化到18 s,并测量了调制频率分别在30 kHz、40 kHz和50 kHz时输出脉冲宽度的变化情况,得到了555.6 W的最高峰值功率,实现了脉冲宽度从163.4 ns到207.9 ns的变化。实验情况证实了用外接信号发生器能有效控制激光器的输出脉冲宽度。     

A high efficient end-pumped TEM<Subscript>00</Subscript> laser with pulse repetition rate of 5 kHz

An end-pumped Nd:YVO₄ laser fiber-coupled diode was designed. A maximum output power of 4.74 W TEM₀₀ mode CW laser was obtained for a pump power of 10.5 W. The optical efficiency and slope efficiency were measured as 45.1 and 57.8% at 1064 nm, respectively. In Q-switching operation, 4.45 W average power at a pulse repletion rate of 5 kHz was produced, with a stability of pulse peak value <2%.     

High-peak-power AlGaInAs quantum-well 1.3-mum laser pumped by a diode-pumped actively Q-switched solid-state laser

We report a room-temperature high-peak-power AlGaInAs 1.36 microm TEM00 laser pumped by a diode-pumped actively Q-switched Nd:YAG 1.06 microm laser. With an average pump power of 1.0 W, an average output power of 140 mW was obtained at a pulse repetition rate of 10 kHz. With a peak pump power of 8.3 kW, the highest peak output power was 1.5 kW at a pulse repetition rate of 5 kHz.     

LD泵浦Nd3+∶GdVO4/Cr4+∶YAG固体激光器

通过合理设计，精密调控各元件和温控电流，得到了平均功率为70mW，脉冲宽度为22ns，重复频率为14 kHz，峰值功率高达230 W的Nd³⁺∶GdVO₄/Cr⁴⁺YAG绿光脉冲激光器.腔外采用望远镜系统聚焦，经KTP晶体倍频后，得到了平均功率为28.8 mW，脉冲宽度为19 ns，重复频率为14 kHz，峰值功率高达108 W的绿光激光输出，转换效率高达.指出了小光斑对倍频晶体带来的影响.     

Operation of electro-optically Q-switched Nd:LuAG laser at 1064 nm

We present the operation of a diode-pumped high-power electro-optically Q-switched 4 W Nd:LuAG laser operating at 1064 nm. At an absorbed optical power of 20 W, the laser described provides a maximum output of 3.5 W average power at a repetition rate of 50 Hz. The output varies up to a factor of 1.3% for about 1 h operation with a peak power of 280 kW, with the laser beam quality in the TEM00 mode.     

LD端面泵浦腔内倍频Yb∶YAG绿光激光器

报道了一种激光二极管（LD）端面泵浦10at％掺杂Yb∶YAG激光晶体（4×4×1 mm）和Ⅰ类临界相位匹配LBO的腔内倍频全固态绿光激光器.为了克服“绿光问题”,采用了两个激光二极管偏振耦合系统.在双路泵浦功率为1.2 W时,获得最高功率为40 mW 525 nm的连续基模激光输出.在腔内插入Cr4＋:YAG饱和吸收体被动调Q,在泵浦功率为1.2 W时,可以获得平均功率为5.2 mW,脉冲重复频率为2.44 kHz,脉冲宽度为51.5 ns,峰值功率为41.7 W的515 nm脉冲激光输出.输出波长发生变化,而且515 nm脉冲激光输出的阈值仅为728 mW.     

Highly efficient in-band pumped Er:YAG laser with 60 W of output at 1645 nm

A high-power Er:YAG laser that is in-band pumped by a high-power cladding-pumped erbium-ytterbium codoped fiber laser operating at 1532 nm is reported. The Er:YAG laser produced 60.3 W of continuous-wave output at 1645.3 nm in a beam with M2 approximately equal to 3 for 82 W of incident pump power and 20 W of TEM00 output with M2 < 1.2 for 32.4 W of incident pump power. The slope efficiency with respect to incident pump power at pump powers of >20 W was approximately 81%. In the Q-switched mode of operation, a slightly modified resonator configuration incorporating an electro-optic Q switch produced pulses of approximately 4 mJ energy and approximately 100 ns (FWHM) duration, corresponding to a peak power of approximately 42 kW at a repetition rate of 1 kHz for an incident pump power of 16.8 W. The prospects for further improvement in continuous-wave and Q-switched performance are discussed.     

96.2 W all-fiberized nanosecond single-frequency fiber MOPA

We report experimental results on a 96.2 W all-fiberized nanosecond single-frequency masteroscillator power amplifier (MOPA) laser working at 1064 nm. An external modulation fiber laser with average power of 0.5 mW and line width of 20 kHz is used as the seed source. Amplifying the seed laser in four stages, a single-frequency laser with pulse duration of 10 ns and peak power of 816.7 W is obtained. The average output power is up to 96.2 W. Further power-scaling of this MOPA structure can be realized since our experiment is only pump-power limited.