Alexander Alexandrov

Wide aperture (more than 500 mm) deformable mirrors for high power laser beam correction

Wide aperture bimorph mirrors for laser beam correction and formation were developed and investigated. Different types of substrates and active piezoceramics materials were considered to fabricate temperature independent shape of the mirror surface and to maximize the sensitivity of the mirror. High reflectivity coatings for different wavelengths were studied.

Adaptive optics and high power pulse lasers

Some peculiarities of the use of adaptive optical elements and the whole system to correct for the aberrations of high power single pulse lasers are discussed in this paper. The examples of the use of adaptive system to correct for the aberrations of some lasers are presented. As a corrector we used bimorph multi electrode deformable mirror while as a sensor - Shack- Hartmann wavefront sensor.

Fast adaptive optical system for the high-power laser beam correction in atmosphere

Key elements of the fast adaptive optical system (AOS), having correction frequency of 1400 Hz, for atmospheric turbulence compensation, are described in this paper. A water-cooled bimorph deformable mirror with 46 electrodes, as well as stacked actuator deformable mirror with 81 piezoactuators and 2000 Hz Shack-Hartmann wavefront sensor were considered to be used to control the light beam. The parameters of the turbulence at the 1.2 km path of the light propagation were measured and analyzed. The key parameters for such an adaptive system were worked out.

Extremely high power CO2 laser beam correction

This paper presents the design of the closed loop adaptive system to measure and correct for the aberrations of CO2 laser radiation. We considered two wavefront sensors - one sensor is based on commercially available IR camera while the second one – on the so-called thing film sensors. Also we present the design of two bimorph deformable mirrors to be used under high power laser radiation. We discuss both positive and negative attributes of these devices and the possibility to use them in the real laser high-power systems.

New Hartmann wavefront sensor for high power CO2 lasers

This paper presents the two types of Hartmann wavefront sensors to measure the aberrations of CO2 laser radiation. One sensor is baser on commercially available IR camera while the second one - on so-called thing film sensors. We discuss both positive and negative attributes of these sensors and the possibility to use them in the real laser systems.

Shack-Hartmann wavefront sensor and its problems

Shack-Hartman wavefront sensors are widely used in scientific investigations of wavefronts and also, as a component of the closed-loop adaptive optical system, intended to correct for laser beam aberrations. This paper presents successful application of such type sensors in the laser systems investigations to obtain high quality laser radiation. Results of investigations of wavefronts of modern high power solid-state lasers are given in this paper.

Femtosecond laser beam correction by means of adaptive optics

Closed-loop adaptive optical system based on phase-conjugate algorithm and including deformable bimorph mirror and Shack-Hartmann wavefront sensor was developed and studied. The examples of application of this system for wavefront correction and improvement of the beam focusability in the femtosecond pulse lasers produced for fundamental research in the field of high energy physics are presented. In several laser systems based on active elements Ti:Al2O3 with the output pulse energy up to 5 J and the pulse power up to 100 TW a Strehl ratio was increased from 0.1 to 0.8 by means of adaptive optics.

Beam Correction in High Intense Lasers

Some peculiarities of the use of adaptive optical elements and the whole adaptive system to correct for the aberrations of high power single pulse lasers are discussed in this paper. The examples of the use of adaptive system to correct for the aberrations of some lasers are presented. As a corrector we used bimorph multielectrode deformable mirror while as a sensor Shack-Hartmann wavefront sensor

Adaptive systems for single pulse lasers

Some peculiarities of the use of adaptive optical elements and the whole system to correct for the aberrations of high power single pulse lasers are discussed in this paper. The examples of the use of adaptive system to correct for the aberrations of some lasers are presented. As a corrector we used bimorph multi electrode deformable mirror while as a sensor - Shack-Hartmann wavefront sensor.

Adaptive optics for femto-second lasers

Summary form only given. Our work presents the latest results in high-power femto second laser beam formation and correction. We discuss the possibility to compensate for aberrations of large aperture TiS active elements and to improve the focusability of laser beam by a factor of 50.