Miniaturized Pulse Compressor of Deep-Etched Gratings

In this paper we propose a miniaturized pulse compressor which can be used to compensate the group velocity dispersion (GVD) that is produced from a commercial femtosecond laser cavity. The compressor is composed of two identical high efficient deep-etched transmittive gratings. Compared with prism pairs, high efficient deep-etched transmittive grating pairs will have the advantages of small size and light weight. With optimized groove depth and duty cycle, 98% diffraction efficiency of the −1 transmittive order can be achieved at wavelength of 800 nm under Littrow condition. The deep-etched gratings are fabricated in fused silica by inductively coupled plasma (ICP) etching technology. With a pair of the fabricated gratings, the input positively-chirped femtosecond pulses of 73.9 fs are nicely compressed into the nearly-Fourier-transform-limited pulses of 43.2 fs. The miniaturized deep-etched-grating-based pulse compressor should be highly interesting for practical applications.