We demonstrate the generation, spectral broadening and post-compression of second harmonic pulses using a thin beta barium borate (BBO) crystal on a fused-silica substrate as the nonlinear interaction medium. By combining second harmonic generation in the BBO crystal with self-phase modulation in the fused-silica substrate, we efficiently generate millijoule-level broadband violet pulses from a single optical component. The second harmonic spectrum covers a range from long wave ultraviolet (down to 310 nm) to visible (up to 550 nm) with a bandwidth of 65 nm. Subsequently, we compress the second harmonic beam to a duration of 4.8 fs with a pulse energy of 0.64 mJ (5 fs with a pulse energy of 1.05 mJ) using chirped mirrors. The all-solid free-space apparatus is compact, robust and pulse energy scalable, making it highly advantageous for generating intense second harmonic pulses from near-infrared femtosecond lasers in the sub-5 fs regime.

随着软玻璃光纤的发展和光纤激光器的进步，越来越多的研究人员采用以软玻璃光纤代替石英光纤的方式，得到高功率中红外超连续谱光源。通过广泛阅读国内外关于氟化物玻璃光纤、硫系玻璃光纤和碲酸盐玻璃光纤等软玻璃光纤产生超连续谱的相关文献，本文综述了近年来利用这三类光纤产生中红外超连续谱光源的研究进展。目前氟化物玻璃光纤在实验中的应用最为广泛，且研发进度较快，获得的中红外超连续谱覆盖范围在2~5 μm，最大输出功率可达30 W；硫系玻璃光纤产生的中红外超连续谱光源带宽可达10 μm以上，但输出功率较低；碲酸盐玻璃光纤由于材料中羟基难以去除，在中红外超连续谱的实验中进展较为缓慢；而氟碲酸盐光纤在近几年发展迅速，可能成为未来中红外超连续谱研究的理想介质。

The random distributed-feedback fiber laser (RFL) is a new approach to obtain a high-power stable supercontinuum (SC) source. To consider both structure simplification and high-power SC output, an innovative structure achieving a kilowatt-level SC output in a single-stage RFL with a half-open cavity is demonstrated in this paper. It consists of a fiber oscillator, a piece of long passive fiber and a broadband coupler, among which the broadband coupler acting as a feedback device is crucial in SC generation. When the system has no feedback, the backward output power is up to 298 W under the pump power of 1185 W. When the feedback is introduced before the pump laser, the backward power loss can be reduced and the pump can be fully utilized, which could promote forward output power and conversion efficiency significantly. Under the maximum pump power of 1847 W, a 1300 W SC with spectrum ranging from 887 to 1920 nm and SC conversion efficiency of 66% is obtained. To the best of our knowledge, it is the simplest structure used for high-power SC generation, and both the generated SC output power and the conversion efficiency are highest in the scheme of the half-opened RFL output SC.

设计研制智能型多功能激光防护镜与自动探测告警一体化复合装置，主要用于各类激光辐射人眼损伤的防护和预警。对防护镜和探测告警系统及智能化复合防护技术进行研究和性能测试，利用防护镜与告警装置的信号互联和联动作用，使防护镜双镜复合，并发出告警信号。结果表明，当激光防护告警复合装置探测到激光入侵时均能以不同方式发出各种告警信号和复合防护响应，包括不同颜色灯光闪烁、音响和振动告警，驱使两个防护镜单元镜组复合，对532 nm、1 064 nm、470 nm、808 nm和700～2 000 nm特定波长激光和超连续谱激光进行有效防护，可通过无线信号互联实现集群联动告警和防护。该激光防护镜与探测告警复合装置具有智能化、模块化、多功能集成的特点，各项性能符合设计要求。