Low-coherence reflectometry for stationary lateral and depth profiling with acousto-optic deflectors and a CCD camera

We describe a new optical low-coherence reflectometer for depth and lateral scanning without moving parts. The reflectometer covers a range of 0.4 and 1 mm in the depth and lateral dimensions, respectively. This level was accomplished by an acousto-optic deflector for lateral scanning and temporal-coherence gating for depth resolution. The ac component of the reflected light was captured by a cooled 16-bit CCD camera with a special readout scheme. As a proof of principle, optical depths of a staggered stack of glass plates were measured.