Fabrication of graded index waveguides in azo polymers using a direct writing technique

Abstract

Fast direct writing of waveguides on polymers using low power continuous-wave lasers has been investigated. Using the cis-trans property of a functionalized sulfonated azo chromophores, we have fabricated graded index waveguides with low loss, which is due to graded index sidewalls. Fabrication is done by exposing the polymer film to a 532nm wavelength laser beam focused to about 5μm spot at the film. Losses were calculated to be 0.48±0.04dB∕cm at 830nm wavelength with no surface deformation. This technique enables us to fabricate integrated optical circuits including directional couplers, dividers, filters, switches, etc., as they are currently investigated in our laboratory.