Passively mode-locked grown-together composite YVO4 /Nd:YVO4 crystal laser with a semiconductor saturable absorber mirror under 880-nm direct pumping

A passively mode-locked grown-together composite YVO 4 /Nd:YVO 4 crystal laser is demonstrated with a semiconductor saturable absorber mirror by 880-nm laser-diode direct pumping.Under the absorbed pump power of 24.9 W,a maximum output power of 10.5 W at the repetition rate of 77 MHz is obtained,corresponding to the optical-optical conversion efficiency of 42.1% and the slope efficiency of 53.4%.The pulse width measured is 33 ps at the output power of 10 W.     

液晶实时掩膜技术制作连续微光学元件

提出制作连续微光学元件的一种新技术———液晶实时掩膜技术 ,阐述了其基本原理和制作方法。基于部分相干光成像理论 ,采用计算机模拟了用实时掩膜制作微透镜和微轴锥镜阵列的过程。同时建立了实验装置进行实验 ,用全色银盐干板 (Kodak 131)通过酶刻蚀得到口径为 118.7μm ,深为 1.32 2 μm的 5 6× 48的轴锥镜的列阵。     

产生钠导引星星群的钠信标激光合/分束技术

研究了脉冲光束的偏振和时序非相干合成技术,通过偏振合束器将两路50 W级500 Hz的589 nm钠信标激光在空间上合为一束光线,成功突破了100 W级μs脉冲全固态钠信标激光输出;利用脉冲激光同步延时器控制两路激光脉冲的时序,使其按先后顺序合成一束脉冲激光,重复频率提升到1 kHz。合束后的激光光束质量M²约为1.41,与单光束的光束质量基本保持一致,光斑抖动性约为40μrad,可满足激光钠导引星自适应光学系统的应用需求。与传统的相干合成方法相比,该偏振和时序非相干合成方案具有结构简单、稳定、效率高的优点,且整个系统无需复杂的相位控制机制,为脉冲激光功率扩展提供了新途径。基于上述技术基础,结合自主提出的精密偏振分光专利技术,在丽江天文台通过一台发射望远镜将四束25 W/束的μs脉冲黄激光发射到钠层,成功产生了四颗钠导引星,这一结果将有助于推动大型地基光学望远镜中多层共轭自适应光学技术的发展。     

High power single-mode large-mode-area photonic crystal fiber laser with improved Fabry-Perot cavity

An Yb3 -doped double-clad large-mode-area photonic crystal fiber (LMA PCF) laser with 103-W single-mode continuous-wave output power is demonstrated using an improved Fabry-Perot (F-P) configuration. The slope efficiency of 83.2% and good beam quality (M2 = 1.2±0.1) are achieved without any thermo-optical problems, dichroic mirror surface damage, and drop of the slope efficiency in this system.     

短波紫外278nm和281nm全固态激光研究

波长介于200~300 nm的短波紫外全固态激光(DPL)具有波长短、光子能量高、波段特殊,可实用化与精密化等特点,在激光精密加工、前沿科学及航空航天领域具有重大应用价值。目前,高功率短波紫外激光实现主要基于Nd:YAG晶体1 064 nm激光四倍频实现266 nm激光输出,然而其实用化特性严重受制于现有的四倍频非线性晶体材料。通过新型高功率高光束质量1.1μm(1 112 nm、1 123 nm)Nd:YAG近红外基频激光研究,并以此为泵浦源,创新性将综合性能优良的紫外CBO非线性光学晶体从紫外三倍频应用拓展到高功率短波紫外四倍频278和281 nm应用的最新研究进展,有望获得一种可实用化高功率新型短波紫外全固态激光源。     

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%.     

高功率准连续微秒532nm激光输出

正全固态激光器(DPL)具有效率高、结构紧凑、可靠性高、可获得高功率和高光束质量输出等优点,因此成为固体激光器的一个重要发展方向。具有高平均功率、高重复频率的绿光激光源可应用于可调谐激光的抽运源、海洋探测、光电对抗、污染检测、激光医疗、同位素分离、激光表演等方面。2005年,日本     

激光钠导引星技术研究进展

望远镜是人类探索宇宙奥秘最重要的科学工具之一。大型地基光学望远镜对天观测时,大气扰动使星光波前畸变导致其实际分辨率大幅下降,是长期困扰高精度天文观测的重大科技问题。因此世界各大望远镜均在竞相发展自适应光学技术,以校正大气造成的波前畸变,使望远镜达到近衍射极限分辨率,这标志着地基光学望远镜正在进入自适应光学望远镜时代。激光钠导引星是用激光激发海拨约90 km电离层中的钠原子产生的人造亮星,作为自适应光学校正的信标源,是自适应光学望远镜的核心技术之一。文中介绍了激光钠导引星技术的原理、方法与国内外发展状况,尤其是该实验室采用的固体激光和频技术,实现了钠D2线光谱匹配和钠层激发匹配的微秒脉冲钠导引星激光,并在国内外大望远镜上使用获得成功。     

High-power ultraviolet 278-nm laser from fourth-harmonic generation of an Nd:YAG amplifier in CsB_3O_5 crystal

We report on the experimental investigation and theoretical analysis of a nanosecond pulse high power ultraviolet(UV) 278 nm laser by fourth-harmonic generation(FHG) of a 1112-nm Nd:YAG amplifier in LiB_3O_5(LBO) and CsB_3O_5(CBO) crystals. The UV laser delivers a maximum average power of 10.3 W at 278 nm with peak power of 36.8 k W under input pump power of 41 W at 556 nm. This is, to the best of our knowledge, the highest output power at the specific UV wavelength of 278 nm. We also performed the theoretical investigation on the FHG with a model in the Gaussian approximation of both spatial and temporal profiles, especially accounting for the two-photon absorption effect in CBO crystal for the first time. The average output power, pulse width, and beam spatial distribution of the UV laser were simulated. The theoretical calculations are in close agreement with the experimental results.