准四能级双掺Tm/Ho钒酸钆激光器

在考虑两种离子发光的动力学进展基础上,描述了2μm双掺铥钬(Tm/Ho)系统Tm→Ho能量转移基本过程,建立双掺Tm/Ho系统准四能级速率方程,得出阈值抽运功率和斜率效率的表达式,并利用得出的结论去分析在液氮制冷下光纤耦合激光二极管(LD)端面抽运掺铥钬钒酸钆(Tm/Ho:GdVO4)激光器实验。通过实验,实现了2μmTm/Ho:GdVO4激光器的运转,在抽运功率14W时,激光输出功率3.5W,光-光转换效率25%,阈值抽运功率838mW,理论和实验有很好的一致性。同时也对实验中观测到的上转换绿荧光现象进行了定性的分析。     

非线性晶体应用于中长波红外固体激光器的研究进展

中波红外3～5μm波段以及长波红外8～12 μm波段的激光处于大气传输窗口,在激光成像、环境监测、激光雷达、激光医疗、化学遥感和红外对抗等领域有着非常广阔的应用前景.基于非线性光学晶体,采用光学非线性频率变换技术在实现中长波红外固体激光输出方面具有明显的技术优势.该方法激光器结构简单,且晶体本身并不参与能量交换,因而没有量子亏损,从而产热很少.同时具有单色性好、宽调谐、高功率等优点.本文针对常用以及新型非线性光学晶体,对其应用于中长波红外固体激光器的研究进展做了详细的总结.     

耦合环形腔马赫-曾德尔干涉仪瞬态响应及应用

对耦合环形腔马赫-曾德尔干涉仪光脉冲瞬态响应进行了理论和数值研究.利用光束追迹法推导了脉冲传输的解析关系,并数值模拟了传输光场随时间的演化.输出脉冲形状可通过控制损耗进行调解,响应速度为皮秒量级.由于马赫-曾德尔干涉仪两输出端口的互补性,在输出端可同时实现光脉冲微分和积分操作.利用损耗控制机制,可实现单通道脉冲微分和积分操作转换.引入增益补偿损耗,可实现脉冲压缩及产生可调单一触发光脉冲.     

Tunable CW Tm,Ho:YLF laser at 2μm

A tunable continuous wave (CW) low temperature operating Tm (6 at.-%),Ho (0.6 at.-%):YLF laser pumped by fiber-coupled diode laser is reported. The maximum output power is 4.16 W at 2073 nm by use of 30% output coupling, the slope efficiency is 33%. A tuning range from 2049 to 2081 nm is achieved with a birefringent filter (BF). The factors that contribute to the output power and tuning range are discussed.     

Widely Tunable cw Diode-Pumped 1.9-μm Tm:GdVO4 Laser at Room Temperature

A widely tunable cw diode-pumped room-temperature Tm：GdVO4 laser is built. Output power of 2.8 W and a slope effic/ency of 22% pumped by a 18 W Fibre-coupled diode laser at 795nm have been obtained. Continuous tunability from 1820nm to 1946nm is achieved. In addition, the factors that contribute to the efficiency of oscillation are studied.     

Efficient Diode-Pumped Tm：YALO3 Laser with a Pump Recycling Scheme

By using a pump recycling configuration, the maximum power of 8.1 W in the wavelength range 1.935-1.938 μm is generated by a 5-ram long Tm：YAIOa （4 at.%） laser operating at 18℃ with a pump power of 24 W. The highest slope efficiency of 42% is attained, and the pump quantum efficiency is up to 100%. The Tm：YAlO3 laser is employed as a pumping source of singly-doped Ho（1%）：GdV04 laser operating at room temperature, in which continuous wave output power of greater than 0.2 W at 2.05/μm is achieved with a slope efficiency of 9%.     

Compensating laser wave-front aberration in atmosphere 1.27 km away with SBS

It is reported that the wave-front aberration produced by atmosphere disturbance can be compensated with nonlinear optics phase conjugate technology. The distance of laser propagating in atmosphere is up to 1.27 km away. The result shows that SBS phase conjugating beam energy can be focus in a little area on target. And the biggest energy of phase conjugating beam on target is up to 142 mJ.     

High-powered millijoule pulse energy Tm3＋-doped fiber amplifier at 2.05μm

A high-powered millijoule pulse energy Tm 3+ -doped fiber amplifier seeded with a Q-switched operation of Tm (4 at.-%), Ho (0.4 at.-%):YVO 4 laser is reported. The output characteristics of the amplified laser are studied at the coupled powers of 0.266, 1.24, and 2.65 W. Maximum output power up to 15.7 W is at 10-kHz repetition rate. Nonlinear effects are not observed from the emitting spectrum and the full-width at half-maximum (FWHM) of the pulse duration is reduced from 40.1 to 25.9 ns at 1.57-mJ pulse energy. The beam quality factor M 2 x = 1.9±0.03, M 2 y = 2.1±0.02 at the output power of 14.5 W is measured using the traveling knife-edge method.     

Cladding-Pumped Tm^3＋-Doped Large-Mode-Area Fibre Laser Highly Efficient Output at Approximately 2μm

A cladding-pumped Tm^3＋-doped fibre laser is carried out to generate continuous-wave output power up to 8.4 W at approximately 2 μm with a slope efficiency of 57% compared to the launched pump power. When the fibre is cooled by water, the slope efficiency increases greatly and the output laser spectrum has a blue shift.     

激光二极管抽运（Tm，Ho）：YLF微片激光器的实验研究

从理论上分析了准三能级(Tm，Ho)：YLF晶体的增益与温度关系，晶体温度的降低和长度的缩短有利于减小重吸收损耗对激光器运行性能的影响。在室温条件下，用2．7w波长为792nm激光二极管端面抽运Tm(原子数分数0．06)，Ho(原子数分数0．004．)：YLF微片激光器，阈值抽运功率为450W，当入射到晶体内的激光二极管功率为1．88W时，2μm激光最大输出功率为328mW，斜率效率为22．5％，光—光转换效率达17．4％。为达到激光最佳运行条件，还探讨了激光二极管波长，抽运光偏振方向以及晶体温度对Tm，Ho激光器性能的影响。