The 1.4–1.8 µm eye-safe lasers have been widely used in the fields of laser medicine and laser detection and ranging. The diamond Raman lasers are capable of delivering excellent characteristics, such as good beam quality concomitantly with high output power. The intra-cavity diamond Raman lasers have the advantages of compactness and low Raman thresholds compared to the external-cavity Raman lasers. However, to date, the intra-cavity diamond cascaded Raman lasers in the spectral region of the eye-safe laser have an output power of only a few hundred milliwatts. A 1485 nm Nd:YVO₄/diamond intra-cavity cascaded Raman laser is reported in this paper. The mode matching and stability of the cavity were optimally designed by a V-shaped folded cavity, which yielded an average output power of up to 2.2 W at a pulse repetition frequency of 50 kHz with a diode to second-Stokes conversion efficiency of 8.1%. Meanwhile, the pulse width of the second-Stokes laser was drastically reduced from 60 ns of the fundamental laser to 1.1 ns, which resulted in a high peak power of 40 kW. The device also exhibited single longitudinal mode with a narrow spectral width of < 0.02 nm.

稀土的发光和激光性能都是由其4f电子在不同能级之间的跃迁产生的。由于稀土离子的独特性能，使得稀土掺杂光功能玻璃无论作为主动还是被动元器件，均在高功率激光系统发挥着重要作用。掺钕磷酸盐激光玻璃和掺铒磷酸盐激光玻璃，具有高稀土离子掺杂浓度、大尺寸和高均匀制备特性，分别是1 um和1.5 um人眼安全波段重频-大能量激光器的重要增益介质材料；光致热折变玻璃及体光栅器件，可实现波长选择和模式选择功能，具有衍射效率高、热稳定性好和抗损伤阈值高等特点，是高功率激光系统中重要的、多功能元器件。文中主要介绍了上海光机所最近几年在掺钕磷酸盐激光玻璃，掺铒磷酸盐激光玻璃以及掺铈的光致热折变玻璃及体光栅器件的研究进展。