激光二极管抽运Tm,Ho:YLF晶体声光调Q激光器

对激光二极管端面抽运Tm,Ho：YLF晶体声光调Q激光器的激光特性进行了研究。根据粒子跃迁和能量传递过程,在考虑能级传递上转换的前提下,建立了Tm,Ho：YLF脉冲激光器的速率方程,得到了初始反转粒子数的解析表达式,分析了能量传递上转换效应对激光上能级反转粒子数的影响。在室温下实现了2μm波长激光的脉冲输出。实验上给出并分析了Tm,Ho：YLF脉冲激光器的平均输出功率、单脉冲能量和脉冲宽度随抽运功率以及声光Q开关调制频率的变化关系。在抽运功率为2．8W．重复频率为9kHz时,获得了平均输出功率为189mW的激光脉冲,光-光转换效率为6．8％。在重复频率为1kHz时,得到最大单脉冲能量为65μJ,峰值功率为0．17kW。     

激光二极管抽运Tm,Ho∶YLF晶体声光调Q激光器

对激光二极管端面抽运Tm,Ho∶YLF晶体声光调Q激光器的激光特性进行了研究。根据粒子跃迁和能量传递过程,在考虑能级传递上转换的前提下,建立了Tm,Ho∶YLF脉冲激光器的速率方程,得到了初始反转粒子数的解析表达式,分析了能量传递上转换效应对激光上能级反转粒子数的影响。在室温下实现了2 μm波长激光的脉冲输出。实验上给出并分析了Tm,Ho∶YLF脉冲激光器的平均输出功率、单脉冲能量和脉冲宽度随抽运功率以及声光Q开关调制频率的变化关系。在抽运功率为2.8 W,重复频率为9 kHz时,获得了平均输出功率为189 mW的激光脉冲,光光转换效率为6.8%。在重复频率为1 kHz时,得到最大单脉冲能量为65 μJ,峰值功率为0.17 kW。     

高脉冲重复频率调Q Tm,Ho:GdVO4激光器

报道了一个高效率连续波和调Q高重频两种运行方式的Tm,Ho:GdVO4激光器.Tm,Ho:GdVO4晶体尺寸4 mm×4 mm×7 mm,a轴通光,液氮制冷到100 K,由发射中心波长为793 nm的光纤耦合激光二极管端面泵浦.Tm,Ho:GdVO4激光连续波输出功率4.0 W,光光转换效率26%.声光调Q条件下输出平均高功率3.9 W,脉冲重复频率10 kHz,脉冲宽度50 ns. 通过减小声光Q开关的开启时间,激光脉冲宽度由50 ns减小至23 ns.在10 kHz重频下,测量最大脉冲能量0.39 mJ , 峰值功率7.8 kW.     

(Tm,Ho):YLF微片激光器的实验研究

报道了一台连续792 nm Ti:Al2O3激光器纵向抽运的(Tm,Ho):YLF微片激光器.在室温条件下,当抽运功率为680 mW时,激光器在2.06 μm波长的输出功率达到90 mW.激光器阈值为380 mW,光光转换效率为13%,斜率效率为26%.     

激光二极管端面抽运室温Tm,Ho:YLF连续固体激光器

报道了激光二极管端面抽运Tm，Ho：YLF固体激光器的输出特性.室温下，选用不同透过率的输出耦合镜进行了实验研究，确定了最佳输出耦合镜透过率为2%. 利用小孔扫描的方法，得到了激光远场的光强分布，证明激光为基横模输出，并且给出了热焦距随抽运功率的变化关系.通过在激光谐振腔内插入两个固体Fabry-Perot标准具的方法，获得了2μm激光的单频输出，阈值功率为250mW，在抽运功率为2.8W时，单频输出功率为118mW.此单频激光器可用作激光振荡器和激光放大器的种子源. 关键词： 激光光学 激光二极管 Tm Ho:YLF固体激光器 单频     

基于单壁碳纳米管调Q锁模低阈值Tm,Ho:LiLuF_4激光器

采用垂直生长法制作的单壁碳纳米管作为可饱和吸收体,结合特殊的低阈值谐振腔设计,首次在Tm,Ho:LiLuF_4全固态激光器中实现了低阈值自启动被动调Q锁模运转.以波长可调的掺钛蓝宝石固体激光器作为抽运源,选用1.5%,3%和5%的输出耦合镜,获得了出光阈值低至52,59和62mW的连续光输出.采用3%输出耦合镜,获得了阈值低至250mW的稳定调Q锁模脉冲输出,调Q包络的脉宽为2μs,调Q包络下锁模脉冲重复频率178.6MHz,最大输出功率154mW,最大的单脉冲能量为0.86nJ,调制深度接近100%.     

高效率电光调Q固体激光器的实验研究

分析了灯抽运电光调Q固体激光器的特点以及影响其峰值功率的原因,提出了用将激光棒两端面切磨一定角度的方法来改善激光器的关门特性,提高激光器的最大注入能量。以一支Φ7 mm×105 mm的Nd:YAG棒为例进行了实验研究,获得了最大可达2.21%的电光转换效率。     

670nm电光调Q陶瓷激光器

为了进一步研究Nd∶YAG陶瓷激光器的红光波段,研制了一台重复频率为1 000 Hz的670 nm电光调Q Nd∶YAG陶瓷激光器.采用三个激光二极管列阵侧面抽运掺杂浓度为1.1at%、尺寸为Φ3×50 mm2的Nd∶YAG陶瓷晶体,根据实验测量的陶瓷晶体热透镜焦距,优化设计了折叠腔的各个参量,并对陶瓷晶体及倍频晶体热...     

新型电光陶瓷调Q光纤激光器

报道了基于OptoCeramic(R)电光陶瓷材料的新型调Q光纤激光器.采用976 nm半导体激光器作为抽运源,电光陶瓷调制器作为Q开关,峰值吸收系数1200 Db/m的高掺杂镱纤作为增益介质构成环形腔激光器.增益光纤的高掺杂浓度使得激光器的腔长得到缩短,输出光脉冲的宽度得到压缩.通过调节电光元件的电压,控制材料的折射率,调节谐振腔的损耗,实现Q开关作用.实验中通过改变腔长、抽运功率和重复频率,研究了脉冲的输出特性.获得最窄脉宽104 ns,重复频率3～40 kHz连续可调的调Q脉冲输出.     

Tm,Ho双掺调Q激光系统理论与实验研究

本文针对Tm,Ho双掺的激光系统,利用速率方程理论,得出了激光各能级的反转粒子数分布规律.通过计算预测出了超过1 ms的时间有巨脉冲的光子输出,脉冲能量为88.4 mJ,脉冲宽度为426 ns.实验采用环形腔声光调Q,Tm,Ho:LuLF为激光介质,三向侧面抽运.自由运转和调Q状态的斜率效率分别为6.36%和2.9%.注入能量3.25 J时,自由运转激光能量103.2 mJ,调Q激光能量为30.3 mJ,对应光-光效率为3.17%,0.93%;注入能量3.5 J时,自由运转激光能量为129.3 mJ,调Q激光能量35.9 mJ,对应光-光效率为3.69%,1.02%.最大的动静比为32.8%.激光脉冲宽度为417.2 ns.如果环形腔能够单向运转,那么得到的激光能量和光-光转换效率都将增大一倍,与预测结果更加一致.     

LD-pumped actively Q-switched Tm,Ho:YLF laser at room temperature

We have investigated acoustic-optical Q-switched Tm,Ho:YLF laser end-pumped by a laser-diode. At room temperature, a 2.067 μm wavelength pulsed output is realized. Average output power, single pulse energy and pulse-width are measured at different incident pump powers and pulse repetition frequencies. When the incident pump power is 2.8 W, a maximum average output power of 189 mW is obtained at the repetition frequency of 9 kHz, and this corresponds to an optical conversion efficiency of 6.8%. The maximum single pulse energy of 65μJ, the shortest pulse-width with full-width at half-maximum (FWHM) of 138 ns and the maximum peak power of 470 W are obtained at the pulse repetition frequency of 1 kHz.     

Diode-end-pumped CW and actively Q-switched Tm,Ho:YLF ring laser

This paper presents CW and acoustic-optical Q-switched Tm,Ho:YLF laser performance in a laser-diode end-pumping figure-eight ring resonator structure at 77 K. Under CW operation, different transmission of output couplers and different cavity length were used to achieve best characteristics of the laser. The maximum power of 1.85 W is achieved with the threshold of 2.09 W, slope efficiency of 28.14% and optical-to-optical efficiency of 20.3% on the condition of 1 m cavity length and 18% transmission. Under pump power of 4 W, laser characteristics under Q-switched operation with different pulse repeat frequency was investigated. Maximum energy of 5.86 mJ is achieved with pulse width of 171.2 ns, peak power of 34.2 kW and dynamic-static ratio about Q-switch laser of 0.62 at pulse repeat frequency 70 Hz.     

Passively Q-switched Tm:YLF laser

Stable passive Q-switching of a Tm: LiYF4 laser is obtained using polycrystalline Cr2+: ZnS as a saturable absorber. The achieved maximum pulse energy of 0.9 mJ and peak power of 65 kW for a pulse duration of ～14 ns represent substantial improvement and highest values for a passively Q-switched diode-pumped Tm laser operating at ～1.9 μm.     

能量传递上转换对Tm，Ho：YLF调Q激光器上能级寿命的影响

根据激光二极管纵向抽运Tm,Ho：YLF激光器的能级跃迁和能量传递过程，在考虑能量传递上转换(ETU)的情况下，建立了Tm,Ho：YLF主动调Q激光器的准三能级速率方程，得出了激光单脉冲能量的解析表达式.在理论上指出，能量传递上转换不但减小了输出单脉冲能量，而且严重减小了激光上能级寿命.实验上给出了在固定抽运功率下，单脉冲能量随重复频率的变化关系，验证了理论所指出的能量传递上转换减小了激光上能级寿命. 关键词： 二极管抽运 Tm Ho：YLF晶体 能量传递上转换 速率方程     

Experimental study of electro-optical Q-switched pulsed Nd:YAG laser

We report the specification of a compact and stable side diode-pumped Q-switched pulsed Nd:YAG laser. We experimentally study and compare the performance of the pulsed Nd:YAG laser in the free-running and Q-switched modes at different pulse repetition rates from 1 Hz to 100 Hz. The laser output energy is stabilized by using a special configuration of the optical resonator. In this laser, an unsymmetrical concave-concave resonator is used and this structure helps the mode volume to be nearly fixed when the pulse repetition rate is increased. According to the experimental results in the Q-switched operation, the laser output energy is nearly constant around 70 mJ with an FWHM pulse width of 7 ns at 100 Hz. The optical-to-optical conversion efficiency in the Q-switched regime is 17.5%.     

Dual-polarization electro-optical Q-switched ceramic laser

A dual-polarization electro-optical Q-switched Nd:YAG ceramic laser was studied. By selecting the appropriate size of calcite crystals, the dual-polarization Q-switched pulse was achieved by characteristics of calcite crystal. Experimental results show that compared with the traditional single-polarization electro-optical Q-switched laser, insertion loss is reduced, dynamic to static ratio is greatly improved, thermally induced birefringence of electro-optical Q-switched Nd:YAG ceramic laser is effective compensated. The output power of 19 W and the pulse width of 13 ns are obtained at the repetition rate of 1 kHz and pumped power of 144 W. The dynamic to static ratio is 71%. The results formed the basis for the further development of the high power and high efficiency ceramic red laser.     

A tunable and single-longitudinal-mode Ho:YLF laser

A 1.94 μm Tm-doped fiber laser pumped tunable single-longitudinal-mode Ho:YLF laser with double etalons was reported for the first time. The maximum single-longitudinal-mode output power of 345 mW at 2051.6 nm was achieved at the absorbed pump power of 11.9 W, corresponding to a slope efficiency of 5.5% and an optical conversion efficiency of 2.9%. By regulating the angle of the F–P etalons, the output wavelength of the laser can be tuned from 2051.6 nm to 2063.3 nm. The single-longitude-mode Ho:YLF laser operating at 2 μm can be used as the seed laser source of coherent Doppler lidar, differential absorption lidar and so on.     

高脉冲重复频率调Q Tm,Ho:GdVO4激光器

报道了一个高效率连续波和调Q高重频两种运行方式的Tm,HoGdVO4激光器.Tm,HoGdVO4晶体尺寸4 mm×4 mm×7 mm,a轴通光,液氮制冷到100 K,由发射中心波长为793 nm的光纤耦合激光二极管端面泵浦.Tm,HoGdVO4激光连续波输出功率4.0 W,光光转换效率26%.声光调Q条件下输出平均高功率3.9 W,脉冲重复频率10 kHz,脉冲宽度50 ns. 通过减小声光Q开关的开启时间,激光脉冲宽度由50 ns减小至23 ns.在10 kHz重频下,测量最大脉冲能量0.39 mJ , 峰值功率7.8 kW.     

Diode end-pumped acousto-optically Q-switched compact Nd:YLF laser

Compact diode end-pumped acousto-optically Q-switched Nd:YLF laser was developed. As in effective CW diode end-pumped lasers, pump beam was made sufficiently narrower than resonator Gaussian mode to increase efficiency in Q-switched operation. The dramatic changes of output radiation structure were observed at some resonator lengths. The radiation structure is close to the Gaussian mode in intervals between these lengths.     

End-pumped optical bistability Tm,Ho:YLF laser

We experimentally demonstrate strong optical bistability in a 2 μm continuous wave Tm,Ho:YLF laser with a bulk crystal. The laser is end-pumped by a 792 nm fiber-coupled laser diode. The bistable region is as wide as 1.6 W and the jump power at the turning point is as high as 82.5 mW when the temperature of the laser crystal is kept at 253 K. The influences of the cavity length and the transmission of the output coupler on the characteristics of optical bistability are obtained. The theoretical analysis shows that the bistable output in the Tm,Ho:YLF lasers comes from the combined effects of the nonlinear saturation of ground state reabsorption, the energy transfer upconversion, and the excited state absorption.