Silver halide planar waveguides and grating couplers for middle infrared integrated optics

摘要

We fabricated silver bromide u0002AgBru0003 planar waveguides with a thickness of u000420 u0002m and designednreflective grating couplers for coupling the radiation of a tunable CO2 laser into these waveguides.nWe found that the attenuation was 6–9 dB/cm. The waveguides were used as attenuated totalnreflection elements for the sensing of hazardous pesticides in water in concentrations higher than 25nppm. This work will pave the way for developing integrated optical elements and circuits which arenbased on silver halides and which operate in a broad spectral range in the mid-IR. These will benuseful as chemical sensors and as spatial elements in nulling interferometry. © 2010 AmericannInstitute of Physics. u0005doi:10.1063/1.3527920