Second order diffractive optical elements in a spatial light modulator with large phase dynamic range

摘要

A study of the diffraction efficiency of a spatial light modulator with a large dynamic phase range is reported. We use a phase-only device that reaches 4n phase modulation depth for the wavelength of 454 nm. This allows operating phase-only diffractive optical elements in the second harmonic diffraction order, instead of in the usual first diffraction order. This type of implementation shows advantages in terms of resolution and diffraction efficiency. Experimental results are reported for blazed diffractive gratings and diffractive lenses.