4 August 2014 CRAO: a compact and refractive adaptive-optics
Author Affiliations +
CRAO is a demonstrator of a compact and low-cost adaptive-optics (AO) with a double-pass lens configuration. Owing to its compact optical layout compared to conventional reflective AOs, the instrument size can be reduced to only 0.03 square meters. We plan to apply this miniaturization technique into future AOs on a variety of telescopes ranging from 1m- to 30m-class. CRAO is installed at a Nasmyth focus of the 1.3m Araki telescope at Koyama Astronomical Observatory in Kyoto Sangyo University. CRAO adopts a closed-loop single-conjugate system with wavelength coverage of 400 - 700 nm and the field of view of 30 arcsec. For low cost, we also employ commercial products on its wavefront sensor (WFS), deformable mirror (DM), and tip-tilt (TT) stage. CRAO is designed to improve the atmospheric seeing from 2.5 to 0.6arcsec under a typical condition at Koyama Astronomical Observatory with 12x12 subapertures in the WFS, 48 electrodes in the membrane DM and the control bandwidth of 200Hz. In order to examine key issues inherent in refractive optical system such as chromatic aberration, temperature aberration and ghost images, room and on-sky experiments are currently underway. CRAO has seen first light in May 2014, and we have confirmed that effects of chromatic aberration and ghost images induced by its refractive optics are negligible for at least TT correction. In this paper, we present experimental results as well as the design of optics, opto-mechanics and control system.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Naofumi Fujishiro, Naofumi Fujishiro, Eiji Kitao, Eiji Kitao, Tomo Shimizu, Tomo Shimizu, Takuya Matsui, Takuya Matsui, Yuji Ikeda, Yuji Ikeda, Hideyo Kawakita, Hideyo Kawakita, Shin Oya, Shin Oya, } "CRAO: a compact and refractive adaptive-optics", Proc. SPIE 9148, Adaptive Optics Systems IV, 91485W (4 August 2014); doi: 10.1117/12.2055776; https://doi.org/10.1117/12.2055776


What can we teach using adaptive optics?
Proceedings of SPIE (July 16 2014)
6.5 m MMT laser guided adaptive optics system overview...
Proceedings of SPIE (October 16 1997)
W.M. Keck Observatory adaptive optics program
Proceedings of SPIE (May 30 1994)
Open-loop performance of a MEMS reflective wavefront sensor
Proceedings of SPIE (September 26 2007)
Come On An Adaptive Optics Prototype Dedicated To Infrared...
Proceedings of SPIE (September 25 1989)

Back to Top