Polymer microcavity dye laser based on a single mode SU-8 planar waveguide

We present a microcavity solid polymer dye laser based on a single mode planar waveguide. The all-polymer device is self contained in the photo definable polymer SU-8 and may therefore easily be placed on any substrate., and integrated with polymer-based optical or microfluidic systems. As the active medium for the laser we use the commercially available laser dye Rhodamine 6C which is incorporated into the SU-8 polymer matrix. The single mode slab waveguide is formed by a 3-step spin coating deposition: a buffer layer of un-doped SU-8, a core layer of SU-8 doped with Rhodamine, and a cladding layer of un-doped SU-8. The refractive index increases with Rhodamine concentration, and the difference between the un-doped buffer and cladding layers and the doped core layer is fine tuned to 0.001, allowing a large gain volume.