High-speed beam scanning technique based on rotating polyhedral mirror

In applications such as continuous-variable quantum information processing, scanning-pumped mid-infrared lasers, and all-optical photoacoustic imaging devices, a beam scanning technique based on a rotating polyhedral mirror and a right-angle reflector was adopted to meet the demand for wide-field, high-speed parallel beam scanning. By theoretically analyzing the effects of key parameters such as the number of facets and size of the rotating polyhedral mirror, as well as the spacing between the polyhedral mirror and the right-angle reflector on the beam scanning range, line scanning speed, and scanning angle, a parallel beam scanning device was designed and experimentally developed. The results demonstrated that when the rotating octahedral mirror was operated at an angular velocity of (π/18) rad/s, the beam scanning trajectory at 52.00 mm from the scanning system covered a range of 27.79 mm, with a linear scanning velocity of 0.032 m/s. The beam maintained near-parallel movement throughout the scanning cycle with parallelism relative to the incident beam of approximately 1.95×10⁻⁵. This parallel beam scanning technique enabled one-dimensional scanning with the following features: a scanning range covering conventional integrated optical chip or small animal sizes, a single-pass scanning time of on the order of seconds, and consistently parallel beam motion. Moreover, the parameters could be adjusted according to specific needs to optimize the scanning range or scanning rate individually, providing technical support for cutting-edge research such as all-optical photoacoustic imaging and multiplexed quantum communication.