Operation of lateral effect photosensitive position sensors using differential time delay mode

We demonstrate the feasibility of operating 1-D lateral effect photosensitive position sensors by measuring the time of delay between the two terminals. This mode has the advantages of a linear response, avoiding the singularities associated with signal normalization, and thus the possibility of achieving higher SNR over the voltage difference mode of operation. This mode has the potential to simultaneously detect the centroids of several light spots modulated at different frequencies using frequency-division multiplexing techniques.