Near-field Holographic Phase Mask

The near-field holographic phase mask is a high-precision diffractive optical element for micro/nano grating fabrication on semiconductor wafers and integrated optical devices. The product uses the 0/1-order diffraction principle. Through self-interference of zero-order and negative-first-order diffracted light, it forms high-contrast interference fringes with the same period as the phase mask, enabling fabrication of small-period, high-precision, and large-area grating structures. The product is manufactured by a holographic process in a cleanroom environment and features high period accuracy, high period uniformity, >98% fringe visibility, and low defect rate. It is especially suitable for DFB lasers, DBR lasers, planar integrated optics, sensors, and biochips, and can be combined with mask alignment equipment for mass production of micro/nano gratings.