Femtosecond fiber laser based micro- and nano-processing

Micro- and nano-processing are performed by using a high energy mode-locked femtosecond (fs) fiber laser. The laser beam has 1030 nm center wavelength, 750 fs pulse duration and up to 10 mu J pulse energy. Firstly, direct writing of optical waveguide inside glass materials is presented and a 3-D curved waveguide is demonstrated. Secondly, by taking advantages of fs laser deterministic damage threshold, micrometer and sub-micrometer features are obtained for surface ablation. Thirdly, fs UV (FHG, 258 nm) laser processing is investigated and nanometer features are obtained. Periodic structures in good order are also found and the patterns extend coherently over many overlapping laser pulses and scanning tracks. It has 100 nm period, 50 nm width and 50 nm depth. Such micro and nano processing method suggests a possible technique to produce nanogratings, microelectronics, or nanopatterned surfaces of micro-sensors for space optoelectronics.