基于多台阶反射光栅的飞秒脉冲压缩装置

反射式光栅对是一种具有负色散性质的器件,可用于飞秒激光脉冲的压缩和展宽,具有无材料色散的优点。给出了一种基于多台阶反射光栅的脉冲压缩装置。该装置为倍密度光栅结构,由两个周期分别为40μm和20μm的四台阶反射式光栅组成。实验得到的衍射效率可以达到70%以上,输入脉冲经过两个光栅的衍射后会按原路返回,从而达到色散补偿的效果。利用此压缩装置,脉冲宽度为66.8 fs的输入脉冲压缩至接近傅里叶变换极限脉冲,即46.6 fs,由此证明只要多台阶光栅效率足够高,此装置就有可能成为不同于棱镜对进行飞秒脉冲腔内和腔外压缩的另一种途径。

Research on a scanner for tilting orthogonal double prisms

The original scanner for tilting orthogonal double prisms is studied to test the tracking performance in intersatellite laser communications. With a reduction ratio of more than 100 times from the change rate of the angle of beam deviation to that of the tilting angle of each prism, the theoretical analysis performed, as well as the verification experiment, indicates that the scanner can meet the requirements of the scanning accuracy superior to 0.5 mu rad with the scanning range greater than 500 mu rad and can facilitate the mechanical structure design. (c) 2006 Optical Society of America.

精密光束偏离装置棱镜组件的光机热分析

以精密光束偏离装置的棱镜组件为有限元模型，进行了光机热集成分析．对棱镜组件的结构强度进行了校核，分析了机械载荷作用下的镜面变形；通过模态分析，给出了装置的动态特性和镜面面形振动幅值的变化情况；最后对棱镜的热弹性变形进行了分析，对棱镜的光学性能进行了评价．结果表明：棱镜组件的最大变形在10nm量级，最大应力为0．403MPa，应力和应变相对于结构的准确度要求和材料的许用应力具有较大的裕度；前后棱镜组件的固有频率都大于550Hz，装置具有良好的动态性能；通过对比棱镜在热-结构耦舍分析和机械载荷下的分析结果，说

频率分辨光学开关法测量飞秒脉冲

阐述了频率分辨光学开关法测量飞秒脉冲的原理，详细分析了模式尺寸效应和非线性效应对飞秒脉冲测量的影响。构建了一台用于飞秒脉冲测量的二次谐波-频率分辨光学开关装置，利用该装置对谐振腔输出的飞秒脉冲及压缩后的脉冲进行了测量。得到了飞秒脉冲的时间宽度及光谱宽度、电场及其相位在时域和频域的详细信息。谐振腔直接输出脉冲的时间宽度为56 fs，光谱宽度为27 nm，时间带宽积为0.686，算法中的最小误差为0.001792。脉冲压缩后的测量结果为27 fs，光谱宽度为92 nm，时间带宽积为1.27，算法误差为0.00

一种使用双棱镜的动态小角度测量方法

提出一种基于正切关系和相位调制技术的动态小角度测量方法。使用双棱镜组成干涉测量臂引导两束平行光至分束棱镜处干涉,通过提取携带被测信息的干涉信号的相位实现动态的小角度测量。由于采用位置探测器(PSD)对测量臂中两平行光束的间距进行测量,简化了测量方程,消除了装置中双棱镜必须对称放置的要求。通过正弦地改变半导体激光器的注入电流在时域内实现对干涉信号的相位调制,形成准外差干涉测量模式,提高了光程差的测量精度。实验验证了该方法的可行性,并讨论了影响小角度测量精度的误差因素。研究结果表明,基于该方法的动态小角度的重

K9玻璃薄膜对离子交换磷酸盐玻璃波导表面保护的优化研究

采用镀K9玻璃薄膜方法来解决离子交换掺铒磷酸盐玻璃波导表面的侵蚀问题,对K9玻璃薄膜的厚度进行了优化研究。测量分析了样品的荧光光谱和荧光寿命,采用光学显微镜和棱镜耦合技术对不同K9玻璃薄膜厚度下制备波导的表面形貌和导光特性进行了表征和测试。结果表明,与掺铒磷酸盐玻璃原材料相比,镀K9玻璃薄膜后荧光光谱保持不变,荧光寿命稍有下降(约0.2 ms);K9玻璃薄膜的厚度在60~80 nm的范围内保护效果最佳。为下一步制备掺铒有源玻璃光波导器件奠定了良好的实验基础。

Miniature pulse compressor of deep-etched gratings

We propose a miniature pulse compressor that can be used to compensate the group velocity dispersion that is produced by a commercial femtosecond laser cavity. The compressor is composed of two identical highly efficient deep-etched transmissive gratings. Compared with prism pairs, highly efficient deep-etched transmissive grating pairs are lightweight and small. With an optimized groove depth and a duty cycle, 98% diffraction efficiency of the -1 transmissive order can be achieved at a wavelength of 800 nm under Littrow conditions. The deep-etched gratings are fabricated in fused silica by inductively coupled plasma etching. With a pair of the fabricated gratings, the input positively chirped 73.9 fs pulses are neatly compressed into the nearly Fourier transform-limited 43.2 fs pulses. The miniature deep-etched grating-based pulse compressor should be of interest for practical applications. (c) 2008 Optical Society of America

Laser diode array side-pumped acousto-optic induced unidirectional operation Q-switched Nd : YAG slab ring laser

A laser-diode array (LDA) side-pumped Nd:YAG slab ring laser is described that incorporates a prism-shaped acousto-optic modulator to enforce unidirectional operation and Q-switching. When pumped by the maximum power of 50 W, Q-switched energies of 3.6 mJ and 50 ns duration, corresponding to a peak power of 72 kW, are obtained. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)01306-9].

基于棱镜实现三倍频谐波分离

基于棱镜的色散特性,提出一种楔形窗口与聚焦透镜组合的方式,解决了高功率激光装置三倍频谐波分离所存在的问题,即三倍频的高通量传输和靶面辐照。结合“神光Ⅱ”装置多功能高能激光系统有关参数进行系统设计,确定了楔形窗口参数,并对其所引起的B积分和间距误差进行了分析。通过实验测试,三倍频传输通量由0.7～1 J/cm2提高到2.8 J/cm2,同时靶面三倍频和二倍频分离间距达到2.85 mm,实现了高功率激光装置高通量传输的三倍频谐波分离。

四区域法消除偏振棱镜缺陷对波片相位延迟测量的影响

在起偏器待测波片检偏器系统基础上提出一种四区域测量波片相位延迟量的方法。调整待测波片和检偏器的方位角,获得相应的四组光强值,通过线性运算得到待测波片的相位延迟量,完全消除了起偏器和检偏器不完全消光带来的误差。由于测量系统中不存在标准波片或其他相位调制元件,允许测量波长仅受偏振棱镜和探测器的限制,因此四区域法可适用于很大波长范围内的波片测量。以λ/4波片为例,理论分析了测量系统利用四区域测量法后的仪器误差为σ≤±3.49065×10-3rad(约0.2°),精度比原算法提高约1个数量级。实验验证了四区域法能有效提高系统精度。

光纤耦合波长复用的全息光盘存储记录

详细描述了用光纤耦合、波长复用的全息光盘仔储光路．指出在全息光盘驱动器即将市场化的今天．由于其光路简单、光学元件较少、性价比高．很有可能成为新的全息光盘驱动器的核心技术之一。由于短波长单模光纤及其双波长光纤分束器件的要求比较高．而用多模光纤进行准单模输出调整．以及用分光棱镜进行光束的分光．同时用对双波长敏感的光致聚合物材料进行存储．其光谱灵敏度均匀．光谱范围互不重叠。实验结果表明．光路结构合理．存储效果良好。

微棱镜与双包层光纤侧面耦合效率的实验研究

对微棱镜与双包层光纤侧面耦合技术进行了研究。用光学胶把尺寸为1mm×1mm×1mm直角棱镜的直角面胶合在尺寸为330μm×170μm的内包层侧平面上，激光束以一定的角度从微棱镜的另一直角面入射并通过它耦合进入双包层光纤的内包层，实验测得耦合效率为86％。该方法可用于双包层光纤的侧面抽运。

空间用调Q偏振耦合输出棱镜谐振腔特性分析

为了优化棱镜谐振腔在调Q状态下的运转特性,充分利用琼斯矩阵光学分析棱镜谐振腔的特性,在不同材料棱镜情况下,比较了可变输出耦合率、泡克耳斯盒的消光比以及输出耦合率的调节.得到泡克耳斯盒在四分之一波长电压下能够得到比半波长电压更高的消光比,从而更适合在调Q工作状态下工作.

Cr^3＋，Yb^3＋，Er^3＋共掺磷酸盐铒玻璃转镜调Q激光性质研究

研究了Cr^3＋，Yb^3＋，Er^3＋共掺磷酸盐铒玻璃转镜调Q激光性质．三种Er2O3掺杂浓度的激光实验结果表明，在Er2O3名义掺杂浓度为0．5wt％时，玻璃的综合激光性质最好，重复频率为0．1Hz时，它的激光阈值功率为14．5mJ，最大输出能量为9．6mJ，斜率效率为0．55％．在同种实验条件下，比较了Cr14和Kigre公司生产的QE-7S激光性质参数，实验表明，前者激光阈值功率稍低，而后者的斜率效率和最大输出功率略高．

Low-loss planar and stripe waveguides in Nd3+-doped silicate glass produced by oxygen-ion implantation

We report on the fabrication and characterization of low-loss planar and stripe waveguides in a Nd3+-doped glass by 6 MeV oxygen-ion implantation at a dose of 1x10(15) ions/cm(2). The dark mode spectroscopy of the planar waveguide was measured using a prism coupling arrangement. The refractive index profile of the planar waveguide was reconstructed from a code based on the reflectivity calculation method. The results indicate that a refractive index enhanced region as well as an optical barrier have been created after the ion beam processing. The near-field mode profiles of the stripe waveguide were obtained by an end-fire coupling arrangement, by which three quasitransverse electric modes were observed. After annealing, the propagation losses of the planar and stripe waveguides were reduced to be similar to 0.5 and similar to 1.8 dB/cm, respectively. (c) 2007 American Institute of Physics.