| 摘要 |
A preferably CMOS-implementable system measures distance and/or brightness by illuminating a target with emitted optical energy having a modulated periodic waveform whose high frequency component may be idealized as S1=cos(omega.t). A fraction of the emitted optical energy is reflected by a target and detected with at least one in a plurality of semiconductor photodetectors. Photodetector quantum efficiency is modulated to process detected signals to yield data proportional to the distance z separating the target and photodetector. Detection includes measuring phase change between the emitted optical energy and the reflected fraction thereof. Quantum efficiency can be modulated with fixed or variable phase methods and may be enhanced using enhanced photocharge collection, differential modulation, and spatial and temporal multiplexing. System power requirements may be reduced with inductors that resonate with photodetector capacitance at the operating frequency. The system includes on-chip photodetectors, associated electronics, and processing.
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