One-step fabrication of polymer components for microphotonics by gray scale electron beam lithography

L. Dong; S. Popov; A. T. Friberg

doi:10.2971/jeos.2011.11010

Journal of the European Optical Society - Rapid publications, Vol 6 (2011)

One-step fabrication of polymer components for microphotonics by gray scale electron beam lithography

L. Dong, S. Popov, A. T. Friberg

Abstract

We demonstrate an application of gray scale electron beam lithography (EBL) for fabrication of three dimensional polymer waveguides and grating output couplers using the SU-8 resist. The groove depths of structure are controlled by choosing a proper exposure dose. Unlike reactive ion etching which is limited by the lag effect, the gray scale EBL allows free combination of groove widths and depths. Shrinking effect which is critical in polymer couplers' writing is taken into account and can be compensated. For better fabrication feasibility, the grating couplers can be simultaneously produced with waveguides with no inter-step alignment required. Therefore, this is a promising technique in manufacturing grating output couplers for polymer based waveguides with high performance in terms of mode matching/confinement and coupling efficiency.

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