AlSb as a material for high index contrast nanophotonics

High contrast materials, i.e., materials with a high refractive index and low optical loss, are of wide interest for nanophotonics metasurface designs at near infrared wavelengths. We explore aluminum antimonide (AlSb) as nanophotonic material, using the design gratings (HCGs) loss dielectric mirrors an example. The refraction absorption coefficient AlSb in visible wavelength range enable HCGs that can be effectively optimized to form 93.5% reflectivity red detail co-sputtering synthesis method films, achieve our target 3.5 635 nm light. also find sensitivity oxidation requires specific handling procedures developing deposition processes yield zero coefficient.