Structured lens formed by a 2D square hole array in a metallic film.

A method is proposed to modulate phase using variant square holes in a metallic film based on a fundamental mode approximation model. Phase retardation through square holes in a subwavelength scale in a thin metal film has been analyzed and calculated. Based on the model, a structured lens with a numerical aperture of 0.583 and a focal length of 240 microm… (More)