IR and UV Femtosecond Laser Micromachining of Si-on-SiO_2 for Photonic Bandgap Crystal Fabrication

摘要

Femtosecond laser pulses with 775nm and 387nm were used to machine Si-on-SiO_2 substrates for photonic bandgap crystals. With 387nm ultrashort UV pulses, we obtained holes as small as 160 nm, which is smaller than half of the laser wavelength with only conventional optics. Moreover, a pitch-size of 420 nm is also obtained in Si-on-SiO_2, which meets the spacing requirement for today's telecommunication frequency - 1550 nm. Ultrafast laser micromachining is fast and versatile so that it is a powerful tool for in-situ microstructure operations such as nanostructuring, repairing, and production industrial applications.