Measurement of Critical Parameters of Terminal Off-Axis Wedged Lenses for High-Power Laser Systems

To address this challenge, a multi-parameter, full-process measurement and alignment method for off-axis wedge lenses is proposed. The proposed method enables high-precision measurement of the off-axis distance, back focal length error, and transmitted wavefront, while also providing an offline alignment scheme for lens installation. Reference transfer is established using a collimator and an optical flat, and a dynamic interferometer is ingeniously employed for optical axis alignment.

In the final measurement configuration, the off-axis distance and back focal length error are transformed into the physical distance between two spatial reference points, allowing them to be measured using conventional distance-measuring instruments, whereas the transmitted wavefront is directly characterized by the dynamic interferometer equipped with a spherical transmission lens. Based on the same reference-transfer strategy, offline installation and alignment of the off-axis wedge lens can also be achieved, ensuring accurate positioning in the operating configuration.

Experimental results demonstrate that the proposed method can simultaneously determine multiple key parameters of an off-axis wedge lens. From six repeated measurements, the variances of the measured off-axis distance and back focal length error were 0.058mm and 0.69mm, respectively. The proposed method features a simple operation, compact workflow, and excellent scalability.

The measured parameters can directly guide optical fabrication, while the subsequent precision alignment provides reliable support for system integration, jointly enabling accurate target irradiation and long-term stable operation of high-power laser systems.