2277-W continuous-wave diode-pumped heat capacity laser

A high power continuous-wave (CW) diode-pumped Nd:YAG laser operated in heat capacity mode is demonstrated by use of two identical highly efficient diode-pumped laser heads placed in a plane-plane resonator.The laser heads are uniformly pumped with a five-fold symmetrical side-pumping configuration, and each head is able to output maximum output power of 2200 W at 808 nm.Under a total pump power of 4290 W,the output power of the laser at 1064 nm is up to 2277 W,corresponding to an optical-to-optical efficiency of 53.1%.     

光抽运垂直扩展腔面发射激光器腔内倍频理论研究

建立了计入光波在非线性晶体中走离和相位失配情况下的光泵面发射激光器腔内倍频的速率方程理论模型,采用循环数值逼近的方法对该速率方程进行求解.以BBO,LBO,PPLN等非线性晶体为例,研究了晶体长度以及抽运功率等因素对倍频输出功率的影响,模拟结果与实验结果符合得较好. 关键词： 光抽运 垂直扩展腔面发射激光器 腔内倍频 数值模拟     

高功率可调谐1064 nm准连续单频激光振荡-放大系统研究

研制了高功率可调谐1064 nm准连续单频激光振荡-放大系统.振荡级采用三镜环形行波腔型结构的Nd:YAG激光器,通过精确控制腔内标准具的温度改变标准具材质折射率和厚度实现了对激光波长的调谐,获得了13.2 W调谐范围为58 GHz的1064 nm准连续单频振荡光,其重复率为1 kHz,占空比为10%.经过由双Nd:YAG激光头串接构成的放大器对振荡光进行双程放大后激光最终输出功率为44 W,光束质量因子M²= 1.58. 关键词： 可调谐激光 单频激光 标准具 振荡-放大系统     

Electronic structure of heavy fermion system CePt_2In_7 from angle-resolved photoemission spectroscopy

We have carried out high-resolution angle-resolved photoemission measurements on the Ce-based heavy fermion compound CePt_2In_7 that exhibits stronger two-dimensional character than the prototypical heavy fermion system CeCoIn_5.Multiple Fermi surface sheets and a complex band structure are clearly resolved. We have also performed detailed band structure calculations on CePt_2In_7. The good agreement found between our measurements and the calculations suggests that the band renormalization effect is rather weak in CePt_2In_7. A comparison of the common features of the electronic structure of CePt_2In_7 and CeCoIn_5 indicates that CeCoIn_5 shows a much stronger band renormalization effect than CePt_2In_7. These results provide new information for understanding the heavy fermion behaviors and unconventional superconductivity in Ce-based heavy fermion systems.     

基于光参量放大相位共轭特性的图像修复与增强

非线性光学相位共轭技术可将经过散射介质后产生畸变的光学波前进行修复.本文基于光参量放大(OPA)过程的光学相位共轭(OPC)特性,进行了光学相位共轭图像修复和增强的实验研究.基于大能量532 nm皮秒抽运激光和大口径非线性光学晶体KTiOPO_4(KTP)(Ⅱ类相位匹配),对经过牛奶乳浊液后已无法识别的1064 nm近红外光学图像,进行相位共轭修复,修复后的图像分辨率达12线/mm,此外,结合OPA过程的光学增益特性,实现了超过17 dB的光学图像增强,为现有三波混频光学相位共轭修复畸变所获图像增益的最大值.在此基础上,峰值信噪比较修复之前有160%的提升.考虑到光参量过程所具有的波长可调谐特性,在实际应用中,可根据需要,选择与生物组织的光学治疗窗口相匹配的成像波长,从而保证更长的穿透深度,提升生物组织成像和医学无损检测的效果.     

LBO-类非临界相位匹配腔内倍频671nm激光器

报道了利用珋类非临界相位匹配的ＬＢＯ晶体腔内倍频、激光二极管泵浦的ＮｄｖＹＶＯ４ 激光器, 在吸收泵浦功率５．４４ Ｗ 时, 获得２４０ ｍ Ｗ 的６７１ ｎｍ 激光输出, 光－光转换效率约４．４％ 。     

High-Efficiency High-Power Nd：YAG Laser under 885 nm Laser Diode Pumping

A high-efficiency high-power Nd：YAG laser under 885 nm laser diode （LD） pumping is demonstrated. The laser crystal is carefully designed, and the overlapping between the pump modes and the laser modes is optimized. The maximum output power at 1064 nm is 87W under the absorbed pump power 127.7 W, corresponding to a slope efficiency of 72.4% and an optical-optical efficiency of 68.1%. The optical-optical efficiency is 58.4% for the pump power emitted directly from the LD. To our best knowledge, this is the maximal optical-optical conversion efficiency obtained for the LD end-pumped Nd：YAG lasers so far.     

High power high beam quality diode-pumped 1319-nm Nd:YAG oscillator-amplifier laser system

This paper demonstrated a high power and high beam quality diode-pumped 1319-nm Nd:YAG master oscillator-power amplifier laser system. A thermally near-unstable resonator with four-rod birefringence compensation flat--flat cavity was adopted as the master oscillator. A solid etalon was inserted in the unidirectional ring resonator to compress the laser linewidth. Under a repetition rate of 500~Hz and pulse width of 160~\mus, the master oscillator delivers an average output power of 16.8~W at 1319~nm with linear polarisation, beam quality factor M^{2} = 1.16 and linewidth of 3.2~GHz. A double-pass power amplifier with two amplifier stages was employed for higher power scaling and the output power was amplified to be 25.9~W with M^{2} = 1.43.     

激光二极管抽运Nd∶YVO4/LBO红光激光器研究

报道了激光二极管抽运的Nd∶YVO4晶体、LBO晶体Ⅱ类非临界相位匹配腔内倍频大功率红光激光器。通过对激光晶体热效应的考虑 ,设计了热不灵敏腔 ,采用低掺杂浓度Nd∶YVO4晶体 ,获得了 6 71nm红光的最高输出为890mW。     

高平均功率调Q准连续Nd:YAG激光器

通过选用低掺杂浓度的Nd:YAG晶体棒、热近非稳腔优化设计、双棒串接热致双折射补偿技术以及双Q开关正交放置结构，在LD抽运功率1116W时，实现调Q准连续全固态Nd:YAG激光器1064nm输出，平均功率达258W，光束质量M²～15.5，重复频率为10kHz，脉冲宽度为64ns，峰值功率达0.4GW，光光转换效率达23.1%. 关键词： Nd:YAG激光器 准连续波 激光二极管抽运 固体激光器