Inverted deposition and high-velocity spinning to develop buried planar chalcogenide glass waveguides for highly nonlinear integrated optics

We report on buried planar waveguides in a highly nonlinear infrared transmitting chalcogenide glass, fabricated using a combination of inverted deposition of the molten glass phase and high-velocity spinning. Films of gallium lanthanum sulphide (Ga:La:S) glass were deposited onto an expansion coefficient matched Ga:La:S cladding substrate. These amorphous films, with an optimized composition designed to be resistant against crystallization, were observed to have an excellent interface quality and uniformity. The designed planar chip had a buried core, 6μm thick in the vertical direction, in single-mode operation at 1.064μm and a measured propagation loss of <0.2dBcm−1. Through this technique waveguides from Ga:La:S glass, a highly versatile optical semiconductor material, can potentially be used in nonlinear applications as well as provide passive and active integrated optic functionality into the infrared beyond 5μm.