Theoretical research of chalcogenide pedestal waveguide gas sensor

Abstract

A rectangular waveguide with a small external confinement factor (γ) limits the gas sensing performance. The fabrication process of a suspended waveguide with large γ is complex. Pedestal waveguide can be fabricated by wet etching on the basis of a rectangular waveguide, which makes full use of the target analyte area under the core layer and increases γ. The TM mode chalcogenide pedestal waveguide was optimized to obtain a large γ. The γ of the optimized TM mode pedestal waveguide is 55.7% and the limit of detection of methane (CH 4 ) for a 1 cm-long waveguide is 1.67%. The fabrication tolerance of the pedestal waveguide was analyzed. The pedestal radius error has a great influence on sensing performance. This work provides a method for the design and performance analysis of a pedestal waveguide sensor.

Fabrication and characteristics of the C3+‐ion implanted and femtosecond‐laser ablated RTP 2D waveguide

“…Considering the importance of waveguides in integrated optics and gas sensing, 9,10 researchers and scientists have been continuously exploring matrix materials suitable for preparing waveguide structures. Rubidium Titanyl Phosphate (RbTiOPO 4 , RTP) is an isomorph of KTP (KTiOPO 4 ) crystal, which is formed when all K atoms in the KTP crystal structure are replaced by Rb atoms.…”