Laser Direct Writing of CGH for Aspherical Surface Testing

Computer-Generated Holograms (CGHs) play a crucial role in aspherical surface testing due to their superior precision, design flexibility, and degrees of freedom. Laser direct writing is emerging as a preferred method for manufacturing CGHs, owing to its low cost, high speed, and efficiency. In this paper, we design a CGH for aspherical surface testing and fabricate it using a self-constructed parallel super-resolution laser direct writing system. The fabricated CGH is then applied to aspherical surface testing. We address various sources of error, including substrate aberrations and binary coding errors, resulting in a significant enhancement in testing accuracy.