Diffractive Optical Element DOE

Diffractive Optical Element (DOE) is a core micro-optical component. It adopts micro-nano lithography technology to fabricate micro-relief phase structures on UV fused silica substrates, and realizes precise wavefront modulation of laser beams through diffraction and interference of light. Different from traditional refractive optical lenses, a single compact DOE can fulfill complex functions including beam shaping, beam homogenization, beam splitting, vortex beam generation and multi-focal spot arrangement. Featuring compact structure and high design flexibility, it is a key optical accessory for high-end laser processing, optical inspection and research optical systems.

All our DOEs are made of UV fused silica. Compared with liquid crystal polymer DOEs, they deliver low absorption, high laser-induced damage threshold and superior compatibility for UV wavelength applications. We support phase level designs from 2-level to 16-level, with diffraction efficiency steadily above 85%. Besides standard products, all models are available for customized development. We can carry out point-to-point phase iterative design according to customers’ laser input parameters, focal length and target light field distribution.

Product Classification & Introduction

1.1 Custom Distribution DOE

It is an open customized DOE mainly for beam shaping and beam homogenization. Based on incident light parameters, system focal length and target output intensity distribution, phase calculation is completed via point-to-point mapping algorithm. Micro-structures are etched by lithography to convert Gaussian beams into any custom light field distribution. Free from standard spot patterns, it is suitable for non-standard laser process development, process iteration and special spot customization.

1.2 Homogenizing DOE

Standard flat-top homogenizing optical element, available in rectangular flat-top and circular flat-top. It converts Gaussian laser into flat-top spot with sharp edge and uniform energy, eliminating the issue of over-high central energy and attenuated edge energy of Gaussian beam, and ensuring consistent irradiation on the working plane. It is the most commonly used standard DOE for industrial laser homogenization, widely used in scenarios requiring uniform surface illumination.

1.3 Spiral Phase Plate DOE (Vortex Phase Plate)

Used to generate vortex beams. Standard specifications include topological charge 1 and topological charge 2; other topological charges are customizable. It modulates wavefront through phase structures with azimuthally varying height. When plane incident light passes through the element, a spiral wavefront is formed, producing an annular vortex beam with a central dark core. The beam carries orbital angular momentum, widely applied in optical tweezers, super-resolution microscopy, optical topography measurement, optical information processing and other advanced optical experiments and equipment.

1.4 Multi-Focal DOE

Outputs 3D multi-focal spots simultaneously. A single element can generate multiple controllable focal points along the optical axis or on the same focal plane. The number of focal points, focal spacing and energy distribution are designed according to optical requirements. One laser beam is split into multiple synchronous focal spots, simplifying optical assembly and avoiding stacking of multiple lenses. Ideal for synchronous laser drilling, layered processing, 3D vision focusing and multi-point synchronous inspection.

General Specification Table

Note: All DOEs are wavelength-locked designs. Nominal optical performance is achieved only at the design wavelength. For customization, please provide laser wavelength, incident spot size, beam mode, working focal length, target spot drawing or light field requirements. Our optical engineers will conduct simulation and design.

Typical Applications

1. Precision Laser Machining: Laser welding, laser cleaning, laser marking, SLM metal additive manufacturing, surface heat treatment, laser coating removal. Flat-top homogenization guarantees consistent processing quality; multi-focal DOEs enable simultaneous multi-point machining; custom spots adapt to special-shaped weld seams and zone energy regulation.
2. 3D Vision & Optical Inspection: Structured light projection, contour scanning, machine vision uniform illumination, LiDAR beam shaping.
3. Scientific Research & Precision Optics: Optical tweezers, super-resolution microscopy, vortex optics, laser interferometry, beam dynamics research. Spiral phase plate DOEs provide stable solutions for vortex beam experiments.
4. UV Laser Applications: UV lithography, UV laser etching, UV precision ablation. Fused silica avoids aging and damage risks of polymer elements with low UV absorption and high damage resistance.
5. Medical Lasers: Homogenized therapeutic spots, multi-point synchronous irradiation optical paths.