Microfluidic channels fabricated by femtosecond laser irradiation and chemical etching for optofluidic devices.

A relatively new technique of Femtosecond Laser Irradiation and Chemical Etching (FLICE) can add nuance to these fabrication approaches and, thereby, permit the development of directly buried microchannels with various aspect ratios. The FLICE fabrication procedure is a two-step process. The first step is femtosecond laser irradiation with intensities below the laser ablation threshold, wherein the design of the microchannels is imprinted into the substrate volume. The second step involves etching of the femtosecond laser modified region using HF acid.In this optofluidic configuration the polymer chains are well isolated; hence we were able to produce optical amplifiers capable of ultra-fast gain switching. By combining the gain and ultra-fast switching properties of PFO in solution with an optofluidic microchannel in a fused silica substrate we were able to produce an easily integratable all-optical amplifier.