Photonic bandpass filter for 1550 nm fabricated by femtosecond direct laser ablation

A bandpass filter, based on the one-dimensional photonic band-gap crystal concept, was fabricated using an ultrafast laser. As predicted by theory, a high-transmission window appeared in the band gap. The photonic crystal operates in the 1550 nm region. A high machining accuracy of similar to15 nm was achieved during our investigation, which is the key for the operability of the photonic device. (C) 2003 American Institute of Physics.