PDMS based waveguides with surface relief Bragg grating

In this paper we present fabrication process of waveguides with surface relief Bragg grating (SR-BG) embossed in poly dimethyl diphenyl siloxane (PDMDPS). Generally, the Bragg grating causes spectral selectivity of propagated light in optical fibers and optical waveguides. We prepared the original concept of fabrication of novel optical waveguides with SR-BG using the laser interference lithography in combination with embossing process of liquid polymer. We used laser interference lithography in Mach-Zehnder configuration to create a grating with period of 21 mu m in thin photoresist layer. In this manner, we created an array of D-shaped waveguides of 10 mu m wide and app. 2.5 mu m high. SR-BG was created in the next step, where the one dimensional surface Bragg grating with period 1.64 mu m was prepared by interference lithography. This period was designed to reflect narrow spectral band close the telecommunication wavelength of 1.55 mu m. Quality of the prepared waveguides and SR-BG was confirmed from atomic force microscope analysis. Transmission and coupling properties of the prepared SR-BG waveguides were finally measured by spectral measurements in infrared spectral region.