During propagation of the high-power laser radiation through atmosphere the quality of the beam is significantly reduced due to atmosphere turbulence. For compensation of the wavefront distortions and improving quality of radiation, as a rule, adaptive optics approaches are used. The design and main characteristics of 121-element water-cooled stacked-actuator deformable mirror for this kind of applications is discussed in this paper.
The correction of the laser beam aberrations and the formation of the laser beam intensity is very important scientific task. This problem widely is being decided at this moment. The employment of the bimorph deformable mirrors for this kind of applications is very promising. But this type of the wavefront correctors has one reasonable shortcoming – low spatial resolution of the control electrodes, it doesn’t allow to compensate for the high-order wavefront aberrations. This kind of aberrations is valuable for imaging applications, mainly if needs to reconstruct specific details. Therefore, we have to use the wavefront correctors with high spatial resolution of the electrodes. In this work we present two types of the bimorph deformable mirrors for solving this problem – multilayer bimorph (multimorph) mirrors and bimorph mirrors with high density of the control electrodes. To place high number electrodes on the piezodisk the laser engraving technology was used, and ultrasonic welding technology used to make the wire connection to these electrodes. We developed the powerful numerical model to simulate bimorph mirrors.
The process of remapping the intensity profile of a laser beam is presented. Bimorph deformable mirror was used to change the beam phase; the control signals for the mirror were calculated in accordance with both phase analysis and far-field intensity distribution measurements.
Formation and correction of the given laser beam intensity and phase is an important practical and scientific problem. Semipassive bimorph flexible mirror is one of the most widely used devices for this purpose. But the key disadvantage of these kind of mirrors is their low spatial resolution of the corrected phase. Mainly this problem occurs when one deals with the small aperture wavefront correctors. In this work we present two approaches to overcome this problem – one to use a multilayer bimorph (multimorph) mirrors and another to put higher density of control electrodes and use a special technique (ultrasonic welding) to make the wire connection to these electrodes. Here we also present a numerical model to simulate bimorph correctors, based on a variation approach of the finite elements method.