A microfluidic dye laser fabricated by nanoimprint lithography in a highly transparent and chemically resistant cyclo-olefin copolymer (COC)

Abstract

We present a polymer-based, microfluidic dye laser suitable for integration into polymer- or silicon-based lab-on-a-chip systems. The laser is fabricated by nanoimprint lithography (NIL) in cyclo-olefin copolymer (COC). The polymer device consists of microfluidic channels, with sizes ranging from several mm down to a few µm, and integrated optical waveguides to couple the light out of the structure, all fabricated in one single NIL step and with approximately 10 nm roughness. COC is a highly transparent, chemically resistant thermoplastic polymer optimal for the integration of microfluidic systems with optical elements. Rhodamine 6G dissolved in ethanol is used as an active medium in the laser, and the resonator is based on multiple reflections from a periodic structure of 16 µm wide, parallel microfluidic channels. Lasing from the device is observed at 577 nm, when optically pumped with a frequency doubled Nd:YAG laser emitting at 532 nm, where Rhodamine 6G has its absorption maximum.