To calculate the control signals of a piezoceramic deflector when measuring the angles of arrival of optical radiation transmitted through atmospheric turbulence, various methods for estimating the beam image in the focal plane of the recording device can be used. The results of numerical studies of the accuracy of calculating the energy center of gravity of an image in the focal plane in several different ways are presented. These methods are used both in split photodetectors and in the Shaсk-Hartmann wavefront sensors.
An optical deflector designed to stabilize the position of the image at the input aperture of the optical system has been developed. The deflector contains an electronic control unit that operates with digital and analog input signals and an actuator based on piezoceramic actuators and a flat mirror. Special design solutions of the actuator ensure that the flatness of the mirror remains in the entire range of correction angles, and the electronic damping system suppresses the vibration of the mirror under a pulsed control signal. Adaptive optics systems with the described deflector are applicable in astronomical telescopes, in ground-based video surveillance and laser scanning systems.
To stabilize the image on the input aperture of the adaptive optics system, a model of the control device for the general angle of inclination of the wavefront is created. The device designed to eliminate image jitter due to atmospheric turbulence and the vibrations of the telescope itself makes it possible to control both the overall wavefront slopes at the input aperture of the system and the wavefront shift along the propagation axis of the beam. For testing the device, a program has been developed that simulates the angles of the wavefront inclination during the formation of an optical beam whose position at the input aperture of the adaptive system is unstable under the influence of atmospheric turbulence.