Compensated telescope system with programmable diffractive optic

• Published in: Optical Engineering 2005-02, Vol.44 (2), p.023201-023209
• Main Authors: Gruneisen, Mark T, Dymale, Raymond C, Rotge, James R, DeSandre, Lewis F, Lubin, Donald L
• Format: Article
• Language: English
• Subjects: aberration compensation; programmable diffractive optic; spatial light modulator; telescope
• ISSN: 0091-3286; 1560-2303
• DOI: 10.1117/1.1849552

Diffractive wavefront control with programmable optically efficient modulo gratings has been successfully demonstrated as a means of compensating large optical aberrations and steering an outgoing beam over small angles without mechanical motion. This work builds on past work to demonstrate the integrated performance of a programmable diffractive element of large pixel count with a telescope system. More specifically, a liquid-crystal-based spatial light modulator is used as a reconfigurable diffractive optical element in a telescope system to compensate for large aberrations associated with variations in object range and field angle within the telescope's field of regard. The telescope consists of a conventional primary mirror that gimbals relative to the other components of the system and a programmable diffractive optic that compensates for more than 40 waves of aberration associated with defocus and off-axis aberrations. In this setup, aberration compensation via the programmable diffractive optic allows the object range to be varied by 160 times the depth of focus and increases the diffraction-limited field of regard by a factor of 70 while maintaining near-diffraction-limited performance. ©