A Nanoimprinted Microfluidic Dye Laser

We present a polymer based microfluidic dye laser suitable for integration into micro total analysis systems, fabricated by nanoimprint lithography (NIL) [1] in the thermoplastic polymer COC (cyclo olefin copolymer) [2]. The device (se figure 1 and 2) consists of microfluidic channels, with sizes ranging from several mm down to 16 μm, and optical waveguides, all fabricated in one single NIL step. For the laser device, Rhodamine 6G dissolved in ethanol acts as active material, and the cavity is based on multiple reflections from a periodic structure of 16 μm wide, parallel microfluidic channels. Pyrex glass wafers are used both as substrate wafer and cover wafer, and since the refractive index of pyrex is lower than COC they also work as buffer and cladding layers for the waveguides in the structure. Lasing from the device is observed at 577 nm (see figure 3), when pumped with a frequency doubled Nd:YAG laser emitting at 532 nm where Rhodamine 6G has its absorption maximum.