Charge-coupled Device Array Detector Research Articles

Wideband Comet Camera Lens Design

A quarter-meter diameter, modified Ritchey-Chretien camera is described for spacecraft-based observation of Halley's Comet. The system will operate over an unusually broad spectral region, from 0.1216 micron (the hydrogen Lyman-alpha line) to 1.1 microns using reflective primary and secondary mirror optics and a thin UV-grade lithium fluoride refractive element as a field corrector near the image plane. The f/12, 3000 mm focal length camera has a 0.4 deg full field of view for operation with a 15 x 15 mm charge-coupled device detector array. The UV-enhanced silicon CCD detector is a 1000 x 1000 array of 15 micron pixels which establishes the system resolution requirement. The optical design and performance are discussed, with an emphasis on the image analysis with respect to pixel resolution elements used for viewing extended objects such as comets.

An integrated optical waveguide and charge-coupled-device image array

The device structure and experimental operation of an integrated optical waveguide and charge-coupled device (CCD) detector array are considered. The use of silicon as a substrate allows direct fabrication of the CCD detector array and a thermally oxidized layer of SiO 2 forms an effective substrate for waveguide deposition. The detector array is composed of a two-phase overlapping-gate CCD with first-level polycrystalline silicon electrodes and second-level aluminum electrodes connected in parallel by means of a series of gates to an array of pbotodiodes. In the photodiode region the SiO 2 layer is tapered to a termination so that with minimal scatter, light is multiply refracted into the detector region. The center-to-center detector element spacing of the device fabricated and successfully operated is 32 μm. Optimum detector length is considered as a function of waveguide thickness. The integrated waveguide-CCD array is expected to become an integral part of various signal-processing devices.