We propose the use of high-index materials for the fabrication of subwavelength diffractive components operating in the visible domain. This approach yields a reduction of fabrication constraints and an improvement of theoretical performance. A blazed grating with subwavelength binary features and with a period of 5.75 wavelengths is designed and fabricated in a TiO2 layer coated upon a glass substrate. The first-order diffraction efficiency measured with a He–Ne laser beam is 83%, which is slightly larger than that achieved theoretically by the best standard (continuous profile) blazed grating fabricated in glass with the same period.
© 1998 Optical Society ofAmerica
Simion Astilean, Philippe Lalanne, Pierre Chavel, Edmond Cambril, and Huguette Launois, "High-efficiency subwavelength diffractive element patterned in a high-refractive-index material for 633 nm," Opt. Lett. 23, 552-554 (1998)