The hybrid model for analyzing distortions of a laser beam passed through moderately scattering medium with the number events up to 10 is developed and investigated. implemented Monte Carlo technique simulate propagation layer, ray-tracing propagate scattered measurements plane, Shack–Hartmann calculate distortions. results obtained from were confirmed during laboratory experiment. Both numerical experiment showed that an increase concentration value particles in range 105 106 mm−3,...

This paper presents the results of processing and systematizing data from laboratory numerical experiments to correct distortions laser radiation propagating through a randomly inhomogeneous medium. The information obtained allows for an accurate estimation effectiveness compensating turbulent fluctuations in refractive index along beam propagation path. Experimentally derived parameters were compared with corresponding values calculated using optical system model. Limitations simulation,...

This paper presents a new development of small-diameter, high-spatial-resolution, semipassive bimorph deformable mirrors to be used in different imaging systems. To manufacture the small control elements, laser engraving technology is used. An ultrasonic welding technique connect wires electrodes (actuators) applied for this kind mirror. The initial flatness mirror surface equals 0.33 μm (P-V) due use substrate polishing after gluing glass piezo disk. We present main parameters these...

The bimorph deformable mirror with a diameter of 320 mm, including 127 control electrodes, has been developed and tested. flatness the initial surface about 1 μm (P-V) was achieved by mechanically adjusting substrate fixed in metal mount. To correct for aberrations improve beam focusing petawatt Ti:Sa laser, wide-aperture adaptive optical system Shack–Hartmann wavefront sensor developed. Correction 4.2 PW laser using provided increases intensity plane to value 1.1 × 1023 W/cm2

Problems of constructing an adaptive optical system intended for correcting the wavefront laser radiation that has passed through a turbulent atmosphere are considered. To ensure high-quality correction, frequency discrete should be at least 1 kHz or more. This performance can achieved by using FPGA as main control element system. The results laboratory experiments beam phase fluctuations caused turbulence, produced airflow fan heater, correction means FPGA-based presented. efficiency was...

Atmospheric turbulence causes refractive index fluctuations, which in turn introduce extra distortions to the wavefront of propagated radiation. It ultimately degrades telescope resolution (in imaging applications) and reduces radiation power density focusing applications). One possible ways researching impact is numerically simulate spectrum reproduce it using a corrector measure resultant using, for example, Shack–Hartmann sensor. In this paper, we developed simulator software that...

The wavefront of the radiation two types from high-power solid-state (Ti:sapphire and Nd:glass) lasers is experimentally studied. measurements are performed using a Shack — Hartmann sensor. technical functional potential this sensor in measuring laser-based schemes demonstrated. results both static dynamic aberrations discussed. estimated dynamics defocus aberration agreement with experimental data.

To correct for phase distortions in high-power laser setups a stacked-actuator deformable mirror with water cooling was developed. The main characteristics of the such as initial surface profile, response functions actuators, maximal stroke and amplitude frequency characteristic were shown. quality equal to 0.14 µm (P-V). about 7 µm. first resonant found at 18.5 kHz, that would allow exploit wavefront corrector high-speed adaptive optical systems. measured hysteresis 12%. Experimental...

Abstract This paper reports a large-aperture adaptive optical system with bimorph deformable mirror and Shack – Hartmann wavefront sensor for aberration correction beam focusing improvement in state-of-the-art petawatt Ti : sapphire lasers. We consider methods providing feedback to the obtaining an objective that optimises onto target. The use of controlled 127-channel 320-mm-aperture laser output power 4.2 PW has made it possible obtain record high intensity: 1.1 × 10 23 W cm −2 .

The rarely considered case of laser beam propagation and focusaing through the moderately scattering medium was researched. A phase-only spatial light modulator (SLM) with 1920×1080 pixel resolution used to increase efficiency focusing radiation propagated 5 mm layer suspension 1 µm polystyrene microbeads in distilled water concentration values ranging from 105 106 mm−3. CCD camera micro-objective estimate intensity distribution far-field focal spot. Shack-Hartmann sensor measure wavefront...

An improvement of laser-focused peak intensity has been achieved in a JAERI 100 TW Ti:sapphire chirped-pulse amplifier chain with feedback controlled adaptive optics system operating at 10 Hz repetition rate. The Strehl ratio was enhanced to 0.8 by means Bimorph deformable mirror Shack-Hartmann wave-front sensor. Measurements optical parameters the laser pulse and an experimental tunneling ionization yield helium have practically confirmed focusing ultrarelativistic intensities over...

In both scientific and industrial laser beam applications is essential for users to know what could be expected from the beam. That why analysis of parameters very important during use in various applications. To describe one can a quality factor <i>M²</i> that characterizes degree imperfection There are many methods determination. The most common way device based on techniques described International Standard ISO11146 "Test parameters: Beam widths, divergence angle propagation...

The rarely considered case when the optical radiation passes through weakly scattering medium, e.g. mid-density atmospheric fog with number of events up to 10 was investigated in this paper. We demonstrated an improvement focusing a laser beam (λ=0.65 µm) passed 5 mm-thick layer suspension 1 µm polystyrene microbeads diluted distilled water. For first time low-order aberration corrector – wide aperture bimorph deformable mirror 48 electrodes configured 6 rings used optimize far-field focal...

This paper presents a FPGA-based closed-loop adaptive optical system with bimorph deformable mirror for correction of the phase perturbation caused by artificial turbulence. The system’s operating frequency about 2000 Hz is, in many cases, sufficient to provide real-time mode. results wavefront laser radiation distorted airflow formed laboratory conditions help fan heater are presented. For detailed consideration, expansion Zernike polynomials is used further statistical analysis based on...

We report a numerical and experimental study of the laser beam propagation through suspension polystyrene microspheres in distilled water, showing presence higher-order centrally symmetric aberrations for scatterer concentrations range from 1.3 × 105 to 106 mm−3 analysing dependence scattered light wavefront distortion on concentration particles turbid medium. The has also shown effectiveness compensation using bimorph adaptive mirror.

Laser beam propagation through a scattering suspension of polystyrene microspheres in distilled water is studied theoretically and experimentally. The dependence wavefront aberrations on the particle concentration investigated. existence symmetric laser passed turbid medium shown.

In this paper we consider two approaches widely used in testing of wide aperture optics: Fizeau interferometer and Shack-Hartmann wavefront sensor. that is common instrument optical can be transformed to a device using sensor, the alternative technique check components. We call Hartmannometer, compare its features those interferometer.

In this paper we consider two approaches widely used in optical testing: Shack-Hartmann wavefront sensor and Fizeau interferometer technique. that is testing can be easily transformed to a device using sensor, the alternative technique check components. We call Hartmannometer, compare its features those of interferometer.

The results of a study the wavefront distortions laser radiation caused by artificial turbulence obtained in laboratory conditions using fan heater are presented. Decomposition terms Zernike polynomials is standard procedure that traditionally used to investigate set existing aberrations. In addition, spectral analysis dynamics makes it possible estimate fraction energy distributed between different modes. It shown related low-order higher compared high-order polynomials. Also, one...

Conventional Shack-Hartmann sensor uses Zernike polynomials in order to approximate the wavefront of light. approximation is well-known, well-established and widely used technique. And most cases quality good enough, especially if measured light beam has circular aperture. But when rectangular or ringshaped (for example, one need measure surface flatness detail that ring-shaped), using fails. In this work we implemented approach Bspline polynomials. We present results a complex simulated...

Atmospheric turbulence causes refractive index fluctuations that introduce extra distortions to the wavefront of propagated radiation. It degrades resolution telescope for imaging applications and reduces radiation power density in focusing applications. One possible ways research impact is numerically simulate spectrum fluctuations, reproduce it using a corrector measure resultant Shack-Hartmann sensor. In this paper, we developed simulator software generates sequence phase screens with...