Curved CCDs and their application with astronomical telescopes and stereo panoramic cameras

Abstract

The creation of curved CCD's and the mosaicing of contoured CCD's mounted within the curved focal planes of telescopes and stereo panoramic imaging cameras introduces a revolution in optical design that greatly enhances the scientific potential of such instruments. In the alteration of the primary detection surface within the instrument's optical system from flat to curved, and precisely matching the applied CCD's shape to the contour of the curved focal plane, a major increase in the amount of transmittable light at various wavelengths through the system is achieved, thereby enabling multi-spectral ultrasensitive imaging for a variety of experiments simultaneously, including autostereoscopic image acquisition. For earth-based and space-borne optical telescopes, the advent of curved CCD's as the principle detectors provides a simplification of the telescope's adjoining optics, reducing the number of optical elements and the occurrence of optical aberrations associated with large corrective optics used to conform to flat detectors. New astronomical experiments may be devised in the presence of curved CCD applications, including 3 dimensional imaging spectroscopy conducted over multiple wavelengths simultaneously, wide field real-time stereoscopic tracking of remote objects within the solar system at high resolution, and deep field mapping of distant objects such as galaxies with much greater precision and over larger sky regions. Stereo panoramic cameras equipped with arrays of curved CCD's will require less optical glass and no mechanically moving parts to maintain proper stereo convergence over wider perspective viewing fields than their flat CCD counterparts, making the cameras lighter and faster in their ability to scan and record 3 dimensional objects moving within an industrial or terrain environment. Preliminary experiments conducted at the Sarnoff Corporation indicate the feasibility of curved CCD imagers with acceptable electro-optic integrity. Currently, we are in the process of evaluatingthe electro-optic performance of a curved wafer scale CCD imager. Detailed ray trace modeling and experimental electro-optical data performance obtained from the curved imager will be presented at the conference.

Highly curved image sensors: a practical approach for improved optical performance

“…Extending lens design optimization to include an arbitrarily curved sensor broadens the set of high quality lens designs. Several recent papers have explored the potentially dramatic performance improvements possible with curved sensor surfaces [1][2][3][4][5][6] including improvements such as 7x reductions in length, 37x in weight, and significantly better modulation transfer function (MTF) and relative illumination, especially at the edges of the image field; the benefits and simplicity of this are evidenced in the human eye [ Fig. 1(A)].…”

Optical analysis of miniature lenses with curved imaging surfaces

“…A general conclusion is that a curved image surface allows designing simpler, more compact, and lower-cost optics [1][2][3]. Recently several researchers have made progress toward developing curved sensors [4][5][6][7][8].…”

Combining freeform optics and curved detectors for wide field imaging: a polynomial approach over squared aperture

“…Several developments of curved detectors have been pursued in recent years by Sarnoff [26], Stanford [27,28], University of Arizona [29] and JPL [30]. Different techniques for the bending of CCD and CMOS detectors have been proposed and the prototypes give promising results, with a very low performance loss in terms of dark current, noise, and a filling factor above 80%.…”