聚四氟乙烯由于具备低介电常数、对0.7~2.5 THz的光传输损耗低等特性，在光子晶体基底材料领域具有广阔的应用前景和巨大的潜在价值。采用飞秒激光器对聚四氟乙烯薄板进行制备二维光子晶体的工艺研究，其中激光器脉宽为388 fs，重复频率为100 kHz。通过对激光烧蚀试验结果拟合，得到聚四氟乙烯薄板在1040 nm波长下的单脉冲损伤阈值为840 mJ/cm²。此外，分析了不同激光参数对二维光子晶体制备工艺结果的影响，发现激光在多脉冲叩击法路径下获得的单层微孔加工质量最好。进一步研究了激光加工功率、扫描速度和扫描次数对圆柱形周期性结构的影响规律，结果表明，在激光加工功率为9 W、扫描速度为100 mm/s、扫描次数为9时能获得结构均匀的微孔阵列。本试验对采用超快激光加工制备聚四氟乙烯二维光子晶体有一定的参考价值。

An improved method for stabilizing a frequency-quadrupled 214.5-nm tunable diode laser system is reported. Improvements to the method include a homemade logic circuit and the use of a Fabry-Perot optical spectrum analyzer as a transfer cavity. Lasers locked with this method exhibit megahertz-level frequency stability measured with an optical frequency comb referenced to a cesium atomic standard. The laser can be locked for hours to days, depending on experiment requirements. Being relatively inexpensive, stable, and robust, the control method can be applied to stabilizing essentially all lasers of deep ultraviolet wavelengths.

We present a 657-nm external cavity diode laser (ECDL) system, where the output frequency is stabilized by a narrow-band high transmission interference filter. This novel diode laser system emits laser with an instantaneous linewidth of 7 kHz and a broadened linewidth of 432 kHz.