No abstract

We describe a new optical low-coherence reflectometer (interferometer) for depth profiling and lateral scanning without moving parts which can also be employed as a stationary FT-JR spectrometer. The reflectometer covers a range of 0.45 mm and 1 mm in the depth and lateral dimensions, respectively. The entire depth range is recorded simultaneously in one scan using a cooled 16-bit CCD camera; the lateral dimension is covered by scanning the probe beam sequentially across the sample with an acousto-optic deflector. The frequency shift generated by this deflector and an additional one placed in the reference arm creates an AC heterodyne signal with a frequency of 2 kHz. Since the CCD camera cannot record the AC signal directly, a special readout scheme is employed. Stationary imaging was demonstrated using an artificial phantom. Using the same interferometer configured as a stationary FT-IR spectrometer, we measured the emission spectrum of an LED with a resolution of 0.74 nm at a central wavelength of 820 nm. We discuss the performance of the stationary CCD imaging system and compare it to that of a singledetector system employing moving parts.

No abstract