Integrating optics and micro-fluidic channels using femtosecond laser irradiation

Abstract

The ability to integrate micro-channels for fluid transport with optical elements is attractive for the development of compact and portable chip-based sensors. Femtosecond Laser Direct Writing (FLDW) in transparent materials is a powerful tool for the fabrication of such integrated devices. We demonstrate the use of FLDW to fabricate coupled micro-fluidic channels and optical waveguides towards an integrated sensing device for molecular detection. Waveguides were directly written into the host material and channels were formed by modifying the molecular structure through FLDW followed by wet chemical etching. Multiple host materials including chalcogenide glasses for IR detection are discussed.

Ultrafast laser inscription: perspectives on future integrated applications

“…Although microchannels have been previously reported in crystalline silicon using microvoid formation , this result offers the possibility of 3D microprocessing using ULI and selective etching in crystalline silicon substrates. In addition to the aforementioned materials, selective etching has also been demonstrated in the chalcogenide glass As 42 S 58 , which is transparent in the mid‐IR spectral region. In this work, a custom built extended‐cavity Ti:Sapphire oscillator with a repetition rate of 26 MHz and a maximum pulse energy of 15 nJ was used.…”