Smart sensing using custom photo-application-specific integrated circuits and charge-coupled device technology

Modern semiconductor technologies make it possible to fabricate photosensors whose geometry and functionality are adapted to specific sensing tasks of various optical measurement techniques. Several such smart sensors, realized with commercially available CMOS/CCD processes, have been demonstrated successfully in different optical sensing applications: (1) a novel absolute position encoder with 10-nm resolution and 50-nm differential accuracy, (2) a dynamic CCD image sensor whose pixel size and shape can be varied in real time, (3) an image sensor capable of carrying out convolutions with arbitrary kernel sizes on-chip and during the exposure, and (4) a 2-D, synchronous detector/demodulator ("lock-in CCD") for applications in heterodyne interferometry and time-of-flight (laser-radar) depth imaging. Several of these devices and techniques rely on dynamic, real-time clocking schemes, for which a universal smart sensor controller was developed, capable of controlling and driving almost any existing CCD/CMOS image sensor at clock rates of up to 25 MHz. The availability of design and fabrication facilities for custom photosensors and imagers, produced quickly and quite inexpensively even in prototype quantities, opens up new possibilities for a wide range of traditional and novel optical measurement techniques.