Publications Details

NIR high-efficiency subwavelength diffractive structures in semiconductors

Smith, R.E.; Warren, M.E.; Wendt, J.R.; Vawter, G.A.

We have fabricated sub-wavelength diffractive optical elements with binary phase profiles for operation at 975 nm. Blazed transmission gratings with minimum features 63 nm wide were designed by using rigorous coupled-wave analysis and fabricated by direct-write e-beam lithography and reactive ion beam etching in gallium arsenide. Transmission measurements show 85% diffraction efficiency into the first order. Anti-reflection surfaces, with features 42 nm wide were also designed and fabricated.