Design for optimized coupling of organic semiconductor laser light into polymer waveguides for highly integrated biophotonic sensors

For downscaling of analytical processes to lab-on-a-chip systems the integration of optical components in microfluidic devices is an emerging issue. We are heading for an all polymer system, which combines optical waveguides with microfluidic channels in one monolithic device. Photodegradation of poly(methyl methacrylate) through deep ultraviolet radiation is used for both, processing of channels and waveguides, respectively. In addition the implementation of organic laser light sources on chip shall allow for the use of exclusively optical interfaces. Creating distributed feedback gratings by hot embossing in poly(methyl methacrylate) and subsequent evaporation of Alq(3):DCM as organic laser active material onto the pattern enables the fabrication of disposable laser light sources. The wavelength of the implemented laser may be tuned about 100 nm around lambda approximate to 630 nm via variation of grating period and height of laser active material. Simulations of waveguide eigenmodes are presented in this paper in order to optimize the coupling of lasers to deep ultraviolet induced waveguides. A concept to realize the highly integrated optofluidic chip with butt coupling of the laser light source to the passive waveguides is shown. (C) 2009 Elsevier B.V. All rights reserved.