The preparation and performance of reticulated targets for the pyroelectric vidicon

Abstract

The spatial resolution of the pyroelectric vidicon may be significantly improved by reticulation of the pyroelectric target. This paper describes the development of techniques and structures for the preparation of high quality reticulated vidicon targets in deuterated triglycine sulphate (DTGS).The dimensions of the reticulated target structures were selected using the results of a theoretical analysis. Reticulated targets were prepared by low energy ion-beam milling of thin targets of DTGS. The ion-beam etching characteristics of this material are described and the selection of masking materials, support layers and the signal electrode are dibcussed. Large numbers of targets were scanned in vidicon tubes so that differences in imaging performance and COSinetic appearance could be correlated to changes made to the target configuration and etching process. From this study an optimum target preparation and processing route was developed which provided significant improvement in rcsolution over tubes possessing planar targets. and also gave acceptable image appearance.

Pyroelectric Materials and Devices

“…9. A theoretical analysis [82] derived the optimum structure with grooves one quarter of the pitch, and reticulation of the DTGS target on a spun polymer support layer of 2 J.1IIl thick was carried out by ion beam milling through an aluminum mask at a pitch of 34 J.1IIl [83]. At high spatial frequencies a thermal MTF improvement by a factor of three was achieved.…”

Progress In IR Television Using The Pyroelectric Vidicon

“…The final aspect leading to improved readout efficiency is lower target capacitance C. Ignoring the mtf factors in equation 2 and multiplying by the efficiency a, is = a pA / unit irradiance (7) 7 While a is close to unity, the signal may be increased by reducing the target thickness d or increasing the scanned area A.…”