RESUMO
A wave-front sensor based on pseudo-phase-conjugate interferometry is presented. We show that a pseudo-phase-conjugate interferometer is suitable for the measurement of phase distribution on a propagating wave. This new method may be employed for optical workshop applications and wave-front sensing for adaptive optics. The theoretical sensitivity of the interferometer is twice that of the Hartmann-Shack wave-front sensor. Preliminary laboratory experiments demonstrate excellent performance and consistency with computer simulations.
RESUMO
We analyze and quantify the capabilities and limitations of a double-conjugate adaptive-optics system. In the proposed system the contribution of two turbulent layers is treated separately, with Rayleigh guide stars for the bottom layer, sodium guide stars for the top layer, and two adaptive mirrors conjugate to the respective layers. The system substantially increases the compensated field of view. We give calculated results for the estimated number of guide stars needed, the wave-front sensor, and the adaptive-mirror resolution. Simulation results are also presented, and the residual error remaining after correction in our proposed system is compared with a conventional single-adaptive-mirror system.
RESUMO
We wish to measure and separate the contribution of atmospheric turbulent layers for multiconjugate adaptive optics. To this end, we propose to create a periodic fringe pattern in the sodium layer and image it with a modified Hartmann sensor. Overlapping sections of the fringes are imaged by a lenslet array onto contiguous areas in a large-format camera. Low-layer turbulence causes an overall shift of the fringe pattern in each lenslet, and high-attitude turbulence results in internal deformations in the pattern. Parallel Fourier analysis permits separation of the atmospheric layers. Two mirrors, one conjugate to a ground layer and the other conjugate to a single high-altitude layer, are shown to widen the field of view significantly compared with existing methods.
