Deformable mirror based on piezoelectric actuators for the adaptive system of the Iskra-6 facility

Wide-Aperture Bimorph Deformable Mirror for Beam Focusing in 4.2 PW Ti:Sa Laser

“…Experiments in high-power laser systems have shown that the real WF aberrations are so-called large-scale [11,12], and, therefore, WF correctors, including the deformable mirrors, should be effective in compensating for such aberrations. In some contemporary wide-aperture lasers, adaptive optical systems include DMs based on piezoelectric actuators and mechanical step motors [13][14][15]. Since such mirrors have local response functions, surface deformation occurs locally, just in the area of each actuator, and thus a large number of actuators is required to compensate for large-scale aberrations.…”

“…Moreover, the pattern of the actuators might print through the mirror substrate (so-called "print-through" effect) [13], which leads to the appearance of undesirable small-scale aberrations (almost like grating), diffraction scattering and additional maxima of intensity in the focal plane. In the future, ultra-high-power lasers should provide multipetawatt pulses with a repetition rate of 10 Hz (ELI HALPS project) [14] or even 100 Hz (GEKKO-EXA project) [15] to initiate laser confinement fusion. It should be noted that mechanical DMs are very slow (the time of one control cycle is more than 0.1 s), which does not allow using them to dynamically correct for the aberrations of each pulse with such a repetition rate.…”

Adaptive Optics and Optical Vortices

“…Next we consider the possibility to transform the wavefronts of the vortex beam by means of the closed-loop adaptive optical system with a wavefront sensor and a flexible deformable wavefront corrector. We can use the bimorph [166] as well as pusher-type [167,168] piezoceramic-based adaptive mirrors as a wavefront corrector. In the experiments a flexible bimorph mirror [166] and the Hartmann-Shack wavefront sensor with a new reconstruction algorithm [157][158][159] are employed.…”

Adaptive Optical Systems in Russian Federal Nuclear Center - VNIIEF with Different Control Principles

“…The beam aperture size is of 200х200 mm, wavelength is 1.053 µ, pulse duration is 3 ns, pulse energy is 3.3 kJ [7]. The wide-aperture deformable flexible adaptive mirror has the aperture size 220х220 mm and 61 piezoelectric pusher-type actuators [8] (see Fig. 8).…”