Mid-infrared characterization of solution-processed As2S3 chalcogenide glass waveguides

An etch-free and cost-effective deposition and patterning method to fabricate mid-infrared chalcogenide glass waveguides for chemical sensing applications is introduced. As2S3 raised strip optical waveguides are produced by casting a liquid solution of As2S3 glass in capillary channel molds formed by soft lithography. Mid-IR transmission is characterized by coupling the output of a quantum cascade (QC) laser (lambda = 4.8 mu m) into the 40 mu m wide by 10 mu m thick multi-mode waveguides. Loss as low as 4.5 dB/cm is achieved using suitable substrate materials and post-processing. Optical absorption and surface roughness measurements indicate that the solution-processed films are of sufficient quality for optical devices and are promising for further development of waveguide-based mid-IR elements. (C) 2010 Optical Society of America