Direct laser-written waveguides for integrated liquid crystal micro-photonics

We demonstrate that Direct Laser Writing (DLW) can be used to print low loss planar polymer waveguides on glass, thus promising a novel soft matter platform for polymer all-optic micro-photonics. We printed straight waveguides with various cross sections and lengths up to 900 mu m on a 500 nm thin layer of low refractive index CYTOP on glass. We also printed two rectangular micro-prisms at each end of the waveguide, which provides coupling of light in and out of the waveguides. The printed structures were imaged and characterized by SEM and we measured the attenuation of light, propagating along the waveguides. While the high refractive index photosensitive resin IP-n162 shows moderate attenuation of similar to 14 dB/cm at 580 nm, the IP-S photosensitive resin shows lower attenuation of similar to 5-9 dB/cm in a rather broad window around 580 nm.