Laser control channels with diffractive optical elements for optical system alignment

Subject of study. A laser control channel for onboard optical system (OS) alignment inspection using diffractive optical elements (DOEs) was studied. Aim of study. The aim was to develop a laser channel for the automated detection of decentering and angular misalignment in OSs using DOEs fabricated by the laser ablation method. Method. A control scheme and measurement technique were developed for detecting defocusing and the angular misalignment of the OS using DOEs. A laser ablation technique for the fabrication of DOEs used in control channels was also developed, and experimental testing of the laser control channel on an OS layout was conducted. Main results. Prototypes of control DOEs fabricated by the laser ablation method were designed and manufactured. A layout of a control channel for the automated detection of decentering and angular misalignment in OSs was developed, which incorporated these diffractive elements. The proposed set of solutions enables the creation of control channels for optoelectronic devices that introduce minimal losses at the operating wavelength while ensuring the accurate measurement of angular misalignment and defocusing in accordance with the functional requirements of the OS. Practical significance. The proposed laser control channel, incorporating DOEs that are fabricated by the laser ablation method, is intended for use in onboard spacecraft as part of automatic OS alignment systems. It can also be used in laboratory settings to determine the mutual positions of lens elements during production and alignment. A key advantage of the proposed control channel is that the diffractive elements do not interfere with the primary radiation beam passing through the OS. The findings of this study can aid in the advancement of existing methods and tools for controlling optoelectronic systems.