Fabrication of optical waveguides by imprinting: Usage of positive tone resist as a mould for UV-curable polymer

Optical ridge type waveguides based on UV-curable polymer were fabricated by imprinting method. Positive tone resist patterned on a silicon wafer was used as a mould. The characterization of waveguides was carried out by coupling TE-polarized light from a tapered fiber into a waveguide with 30 mm length and mapping the intensity distribution with another tapered fiber at the output facet of a waveguide. Proper single- or multimode operation was observed depending on the waveguide width being either 2 µm or 6 µm. Experimental observations on the mode profiles were also supported by the simulation results. Average power transmissions of 32% at 1530 nm wavelength and 45% at 1310 nm wavelength were characterized. The results suggest that the simple mould fabrication process might be a useful technique for device prototyping and that the performance of replicated waveguides can meet the requirements for certain applications.