The steady-state stimulated Raman scattering (SRS) gain with different excitation wavelengths ranging from 400 to 1100 nm of tungstate crystals, SrWO4 and BaWO4, is systematically researched. As excitation frequency is close to electronic transition frequency, molecular polarizability is not a constant, which has to be taken into account in our work. The experiment and theory agree well with each other and show that SRS gain is not only proportional to Stokes light frequency, but is also inversely proportional to biquadratic excitation frequency.

针对45 nm及以下节点光刻相关技术的研究需求，确定了实验型投影光刻物镜的结构型式及设计指标。依据像差理论在非同心小遮拦的Schwarzschild反射系统中添加折射补偿镜组来进一步减小系统的中心遮拦，扩大像方数值孔径。设计了一套小中心遮拦，数值孔径为1.20的Schwarzschild折反式投影光刻物镜。设计结果表明，该投影光刻物镜工作带宽为100 pm，像方视场为50 μm，线中心遮拦比为13%，光学分辨力为80 nm时（6240 lp/mm）的系统调制传递函数大于0.45，全视场最大畸变为6.5 nm，满足了45 nm深紫外（DUV）浸没光刻实验平台对投影光刻物镜的需求。

With a plano-concave cavity, diode-pumped continuous-wave (CW) and actively Q-switched Nd:YVO4 laser operating at 1.34 \mu m is demonstrated. Maximum CW output power of 4.76 W and Q-switched average output power of 2.64 W are obtained with output coupler (transmission T=3.9%). For the Q-switching operation, the theoretically calculated pulse energy and pulse width, with a pulse repetition frequency (PRF) range of 5–40 kHz, coincide with the experimental results. With a T=11.9% output coupler, the maximum peak power of 24.3 kW and minimum pulse width of 6.5 ns are obtained when the PRF is 10 kHz. To the best of our knowledge, this is the shortest actively Q-switched pulse duration ever obtained in a 1.3-\mu m Nd-doped vanadate laser.

研究了SrWO4晶体在外置谐振腔条件下对于皮秒激发脉冲的受激拉曼散射特性。采用提拉法生长了高光学质量的SrWO4晶体,尺寸为22 mm×40 mm,质量为72.3 g。利用分光光度计测量了SrWO4 晶体的室温透过光谱,其透过短波限为260 nm,长波限大于3200 nm,因此可在较宽波长范围内实现拉曼激光频移。当激发源为脉宽40 ps的Nd:YAG锁模激光时,多波长拉曼输出的总转换效率达到73%,最大输出能量2.58 mJ;1180 nm一级斯托克斯拉曼输出的最高转换效率为38%,最大输出能量1.04 mJ;1324 nm二级斯托克斯拉曼输出的最高转换效率为19.3%,最大输出能量0.39 mJ。实验表明,SrWO4晶体具有易生长、透光波段宽、增益系数大、转换效率高等优点,是一种有实际应用前景的固体拉曼介质。

采用腔外单次通过方式, 实现了BaWO4晶体的高效受激拉曼散射(SRS)。当抽运光为532 nm皮秒激光脉冲时获得了5级斯托克斯线(559.64 nm,590.26 nm,624.42 nm,662.76 nm,706.18 nm)和3级反斯托克斯线(463.42 nm,484.24 nm,507.04 nm), 测量了BaWO4晶体各级拉曼散射谱线的阈值和增益系数, 受激拉曼散射的整体转换效率高达78%。当抽运光为355 nm皮秒激光脉冲时观察到3级斯托克斯线(366.52 nm, 379.40 nm, 393.22 nm), 根据一级斯托克斯线的抽运阈值得到相应的拉曼增益为51.8±2.7 cm/GW。实验表明BaWO4晶体具有易生长、透光波段宽、抗光损伤能力强、增益系数大等优点, 有望在全波段可见激光的产生方面获得重要应用。

采用熔体提拉法生长出了高质量的a轴和c轴GdVO4单晶。测量了GdVO4晶体的室温透过光谱, 结果表明GdVO4晶体的短波透过截止边为338 nm, 长波透过截止边大于3000 nm, 透过范围覆盖紫外、可见、近红外和部分中红外波段, 因此可以在较宽波长范围内实现拉曼激光频移。研究了GdVO4晶体在532 nm和355 nm皮秒激光脉冲抽运下的受激拉曼散射(SRS)。采用腔外单次通过方式, 获得了3级斯托克斯线(557.98 nm,586.86 nm,618.92 nm)和1级反斯托克斯线(508.01 nm), 得到GdVO4晶体一级斯托克斯拉曼散射的稳态增益系数为26.6±0.2 cm/GW, 二级斯托克斯拉曼散射的稳态增益系数为14.0±0.2 cm/GW, 受激拉曼散射的整体转换效率达到43%。报道了GdVO4晶体355 nm激发的受激拉曼散射, 观察到2级斯托克斯谱线(365.9 nm,378.1 nm), 在此条件下测得一级斯托克斯谱线的拉曼增益高达114±9 cm/GW。

采用大功率半导体激光器端面泵浦Nd∶LuVO₄晶体，利用Cr⁴⁺∶YAG晶体作为可饱和吸收元件，实现了1．06μm激光的被动调Q运转．在泵浦功率为19．1W时，获得最高平均输出功率为4．58W，脉冲宽度为84ns，单脉冲能量为36．6μJ以及峰值功率为436．2W的激光脉冲．

研究了系列Ce∶Fe掺杂以及不同后处理态(生长态、还原态和氧化态)铌酸锂晶体的透过率光谱和光折变全息存储特性。实验结果表明单掺Ce铌酸锂晶体具有较好的图像存储质量和较宽的透过率光谱范围，二波耦合增益相对较低；高掺杂铌酸锂样品的透过率光谱范围较窄,光折变二波耦合增益较低。晶体的后处理对铌酸锂样品的光折变特性影响明显，双掺Ce∶Fe还原态铌酸锂晶体具有较高的二波耦合增益；氧化态样品具有较大的透过率光谱范围；还原态样品具有较大的光折变二波耦合增益特性。实验结果还表明在同种样品中难于同时获得大的二波耦合增益和图像存储质量。

Cat mutually pumped phase conjugation configuration is discovered and investigated by using two-wave mixing in (K_(y)Na_(1-y))_(2z)(Sr_(x)Ba_(1-x))_(1-z)Nb_(2)O_(6) (KNSBN) crystal. When only one signal or pumped beam does not give birth to phase conjugation, the maximum reflectivity of signal and pumped beam attain 140% and 30% due to two-wave mixing, respectively. The experimental results show that the two-wave mixing can reduce the threshold of incident beams power, extend the incident angle range, and shorten response rate in the process of self-pumped phase conjugator (SPPC) in KNSBN crystal.