title: Optical loss reduction in high-index-contrast chalcogenide glass waveguides via thermal reflow.
abstract: A thermal reflow technique is applied to high-index-contrast, sub-micron waveguides in As(2)S(3) chalcogenide glass to reduce the sidewall roughness and associated optical scattering loss. We show that the reflow process effectively decreases sidewall roughness of chalcogenide glass waveguides. A kinetic model is presented to quantitatively explain the sidewall roughness evolution during thermal reflow. Further, we develop a technique to calculate waveguide optical loss using the roughness evolution model, and predict the ultimate low loss limit in reflowed high-index-contrast glass waveguides. Up to 50% optical loss reduction after reflow treatment is experimentally observed, and the practical loss limiting factors are discussed.
authors.affiliation: Microphotonics Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. hujuejun@mit.edu
authors.forename: Juejun
authors.initials: J
authors.lastname: Hu
authors.forename: Ning-Ning
authors.initials: NN
authors.lastname: Feng
authors.forename: Nathan
authors.initials: N
authors.lastname: Carlie
authors.forename: Laeticia
authors.initials: L
authors.lastname: Petit
authors.forename: Anu
authors.initials: A
authors.lastname: Agarwal
authors.forename: Kathleen
authors.initials: K
authors.lastname: Richardson
authors.forename: Lionel
authors.initials: L
authors.lastname: Kimerling
mesh_terms: D018011:Chalcogens / Q000737:chemistry*; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005898:Glass / Q000737:chemistry*; D006358:Hot Temperature; D008422:Materials Testing; D055096:Optical Devices; D044367:Phase Transition; D012031:Refractometry / Q000295:instrumentation*
chemical_list: D018011:Chalcogens