Spatially resolved spectral interferometry for determination of subsurface structure

We describe an instrument capable of obtaining two-dimensional images of subsurface structure in real time with no moving parts. The technique is based on spectral interferometry and uses an imaging spectrograph to obtain spatially resolved spectra. A test sample consisting of microscope coverslips and a Ronchi grating was measured, illustrating the system's depth resolution of 38 mu m and transverse resolution of at least 12.7 mu m. The technique is readily adaptable to endoscopic delivery as well as three-dimensional real-time image acquisition. (C) 1999 Optical Society of America.