HIGH-EFFICIENCY BINARY PHASE-TRANSMISSION-GRATING USING E-BEAM LITHOGRAPHY

Rigorous coupled-wave analysis indicates that diffraction efficiencies greater than 99%, are feasible for dielectric phase-gratings with a r ectangular profile. The use of rectangular rather than blazed profiles implies simplified fabrication techniques, since deep-etch submicrome tre structuring techniques can be utilized. We identify several parame ter combinations with high diffraction efficiencies using rigorous cou pled wave analysis, demonstrate experimentally diffraction efficiencie s of 94% in a Bragg mount configuration at a wavelength of 543 nm and discuss the influence of substrate thickness on the transmitted light intensities. A direct writing electron-beam lithography fabrication pr ocess gives wide flexibility in design realization.