Preferential chemical etching of blazed gratings in (110)-oriented GaAs

Blazed gratings with a theoretical blaze angle of 35 degrees 16' are etched into (110) GaAs surfaces by preferential chemical etching, using a photoresist mask. A maximum total diffraction efficiency of 15% was measured at 6328 A from a blazed grating with a 2.23-microm period, and the diffracted light was concentrated in a single order. To demonstrate the applicability of such gratings in integrated optics, gratings with periods in a 3000- to 5000-A range were made, and epitaxial growth on (110) GaAs substrates was carried out using a method of growth that deposits high-quality, nearly defect-free layers on such substrates.