An indirect time-of-flight measurement technique for sub-mm range resolution using impulse photocurrent response

This paper presents a new ToF measurement technique using an impulse photocurrent response. In the proposed technique, a laser with a short pulse width for light source, which can be regarded as an impulse input for a detector. As a result, the range calculation is determined only by photocurrent response of the detector. A test chip fabricated in a 0.11um CIS technology employs a draining-only modulation pixel, which enables a high speed charge modulation. The measurable range measured to be 50 mm within nonlinear error of 5% and the average range resolution of 0.21 mm is achieved.