【International Papers】Binary phase-only gallium oxide diffractive optical element for beam shaping

日期：2025-03-11阅读：54

Researchers from the The University of Utah have published a dissertation titled "Binary phase-only gallium oxide diffractive optical element for beam shaping" in scientific reports.

Abstract

This study presents an experimentally validated demonstration of an inverse-optimized binary phase-only gallium oxide diffractive optical element (DOE). This DOE transforms an incident Gaussian beam into a square flat-top beam at the working plane. The design methodology for this binary phase-only DOE beam shaper is founded on an efficient process that integrates the modified Gerchberg-Saxton algorithm and the adjoint method. Experimental characterization of the fabricated device on a single crystal (-201) gallium oxide substrate is conducted at a wavelength of 532 nm, confirming its ability to transform an incident Gaussian beam into a focused square flat-top beam. Such a device holds significant promise for various high-power laser applications, notably in laser welding and similar domains. Furthermore, because of the ultrawide bandgap of gallium oxide, DOEs operating at shorter wavelengths in the UV are also possible based on this technique.

Fig. 1. (a) Schematic of the binary DOE converting Gaussian incident wave to the square flat-top. (b) Flow chart of the proposed adjoint assisted GS algorithm.

Fig. 2. Simulation results with square flat-top target: (a) target diffractive pattern, (b) iterations vs. efficiencies, (c) optimized phase distribution of the binary DOE (blue denotes 0, red denotes π), (d) simulated diffraction pattern at working plane, and (e) averaged irradiance profiles of the diffraction pattern.

DOI：

doi.org/10.1038/s41598-025-89663-0