Optical loss reduction in high-index-contrast chalcogenide glass waveguides via thermal reflow.
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.
Hu
Juejun
J
Microphotonics Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. hujuejun@mit.edu
Feng
Ning-Ning
NN
Carlie
Nathan
N
Petit
Laeticia
L
Agarwal
Anu
A
Richardson
Kathleen
K
Kimerling
Lionel
L
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*
D018011:Chalcogens