Enabling patterning of polymer optical devices working at visible wavelength using thermal nano-imprint lithography

Thermal Ultraviolet NanoImprint Lithography is a fast and reliable process to manufacture large scale integrated polymer-based optical components from a soft stamp. This technology already provides polymer integrated components for optical communications operating in the infrared region. However, several fabrication issues must be addressed to enable reliable mass production of optical components working in the visible region, especially when patterning large devices with nanometric features. In this work, we report our fabrication results on grating coupler and optical microring resonators with SU-8 resist. The device is conceived for monomode visible wavelength operation dedicated to future optical sensing applications. For this purpose, sub-micron waveguides are needed. We reported two main defects on soft stamp fabrication: partial sidewall detachment and shifted or double embossing of the features. Nanoimprinting SU-8 waveguides was achieved with the operational devices of the soft stamp.