Zobrazeno 1 - 10
of 43
pro vyhledávání: '"S. Enguehard"'
Autor:
B. Hatfield, S. Enguehard
Publikováno v:
Progress in Quantum Electronics. 19:239-301
This paper is a pedagogical review of several new methods and solutions to calculate the performance and limits of phase-only compensating adaptive optics systems.
Publikováno v:
SPIE Proceedings.
The symmetry operation associated with propagation reciprocity is complex conjugation and adaptive optics is used to physically carry out this symmetry operation. We use a plane-to-plane framework to describe the fundamental limits placed on implemen
Autor:
B. Hatfield, S. Enguehard
Publikováno v:
SPIE Proceedings.
We discuss the reliance on backscatter by a laser guide star to generate a propagative probe and we show that spatial reciprocity can be accomplished by compensating phase alone. An analytic plane to plane propagation framework is introduced in which
Autor:
S. Enguehard, B. Hatfield
Publikováno v:
SPIE Proceedings.
We investigate a fundamental limit of atmospheric compensation for adaptive optical systems that use uncooperative beacons or laser guide stars. Laser guide stars are generated by backscattering processes that are naturally incoherent. The limit aris
Publikováno v:
SPIE Proceedings.
The limits to the ability of adaptive optics to achieve spatial propagation reciprocity are determined by diffraction. The beacon is a prominent component in defining the diffractive limit, so diffraction plays a role in the optimal choice of beacon
Publikováno v:
2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720).
The individual elements or apertures in a fiber optical phased array are finite in size and range from a few to many wavelengths in diameter. Therefore, the beam from each aperture cannot be characterized by a single phase. Hence, phasing a fiber opt
Publikováno v:
2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720).
Liquid crystal optical phased arrays are rewritable kinoform diffractive optical elements. The control solution for such devices can be based on design optimization algorithms for diffractive optics. Diffractive optical control was demonstrated on a
Publikováno v:
SPIE Proceedings.
The SOPHI (Segmented Optics PHase Integration) Phase 1 project has demonstrated the original goals for the SOPHI breadboard to enable it to meet the challenge of the Phase II full 1 meter optical quality segmented mirror project: one of these goals i
Autor:
S. Enguehard, B. Hatfield
Publikováno v:
Proceedings, IEEE Aerospace Conference.
Optical phased arrays (OPAs) are equivalent to kinoform diffractive optical elements or holograms imparting a phase profile on a laser beam. Unlike static diffractive elements, OPAs are active, dynamical, and rewritable. These dynamical components ca
Autor:
S. Enguehard, B. Hatfield
Publikováno v:
Proceedings, IEEE Aerospace Conference.
The pixelized nature of optical phased arrays (OPAs) or spatial light modulators such as liquid crystal devices (LCDs) or micro electromechanical devices (MEMs) allows us to treat these devices as segmented active optical elements. The individual OPA