Optical properties of thin film novel Chalcogenide materials and optical design for trace-gas sensing

Continuous progress in science, technology, and clean environmental regulations for energy requires low-power chip scale devices in sensing applications. Conventional trace gas sensing in the midinfrared region is highly sensitive. However, it requires a complex optomechanical setup that may not be suitable for wide-area deployments. This paper shows the development of new waveguide materials for near and mid-infrared silicon photonics ranging from 0.7 to 10 mm. These include amorphous semiconductors like Chalcogenide Glasses (ChGs) of Germanium-Selenium-Silicon (Ge-Se-S) elements with different compositions. UV-Vis measurements show the optical energy gap between 1.6 eV with high Se concentration to 3.8 eV, where Se is replaced by S in the compositions. ATRFTIR measurements show a high transmission spectrum ranging from 4000 to 400 cm(-1). We show the optical properties of such thin film materials in the broadband range of mid-infrared, suitable for fabricating waveguides and micro-resonator cavities for on-chip sensing applications.