Broadband long-wavelength infrared Si/SiO2 subwavelength grating reflector

A long-wavelength IR broadband reflector is demonstrated using a high-index-contrast subwavelength grating based on a Si/SiO2 system. The field response has been computationally and experimentally verified to exhibit broadband reflectance in the spectral range of 13-16 μm with Δλ/λ=18.5% for reflectance >70%. The gratings exhibit incident field polarization dependence with an average extinction ratio of 1:1.6.