Integration of active and passive polymer optics

Abstract

We demonstrate a wafer scale fabrication process for integration of active and passive polymer optics: Polymer DFB lasers and waveguides. Polymer dye DFB lasers are fabricated by combined nanoimprint and photolithography (CNP). The CNP fabrication relies on an UV transparent stamp with nm sized protrusions and an integrated metal shadow mask. In the CNP process, a combined UV mask and nanoimprint stamp is embossed into the resist, which is softened by heating, and UV exposed. Hereby the mm to microm sized features are defined by the UV exposure through the metal mask, while nm-scale features are formed by mechanical deformation (nanoimprinting). The lasers are integrated with undoped SU-8 polymer waveguides. The waferscale fabrication process has a yield above 90% and the emission wavelengths are reproduced within 2 nm. Confinement of the light on the chip is demonstrated, and the influence on the laser wavelength from temperature and refractive index changes in the surroundings is investigated, pointing towards the use of the described fabrication method for on-chip polymer sensor systems.