Spatial filtering by a line-scanned nonrectangular detector: application to SPRITE readout MTF.

Any finite-sized photodetector has an effect on the spatial frequency content of the detected image. An expression for the modulation transfer function (MTF) of a nonrectangular detector in the along-scan direction is obtained. A comparison of our theoretical prediction is made with published experimental and numerical values for the MTF of a photosite having an exponentially tapered shape. Structures of this form are used as the readout region in SPRITE (signal processing in the element) detectors.