Optical properties of ZnSe diffractive optical elements for spot array generation

The diffractive optical element (DOE) is a revolutionary technology for sophisticated optical systems. It has recently been launched within the optical industry, which is constantly seeking improvements over conventional optics. We have designed and fabricated three types of binary-phase DOE and a 4-level phase DOE for spot array generation. The surface relief of a ZnSe substrate was patterned and etched with each intended phase distribution by using photolithography and reactive ion etching (RIE) technologies. The optical properties of anti-reflection coated samples were then examined by measuring the intensity distribution of the converging beams and the results compared with the calculated beam propagation.