Abstract: A method and apparatus for imaging teeth includes illuminating a surface of a tooth and electronically imaging the tooth from a non-illuminated surface of the tooth with an electronic camera. Automatic control of the intensity of illumination is preferably provided to avoid saturation of the camera. The camera may include a charge-coupled-device and the resulting digital images are preferably enhanced by wavelet analysis. If a video camera is used, the images may be digitized and then enhanced. Current images of the tooth may be compared to prior images of the same tooth to monitor changes in the tooth over time. The images can be used to detect dental caries and other dental conditions. A handpiece for illuminating the tooth and receiving the light passing through the tooth for reception by the camera in a reproducible manner, is also described.

Abstract: Common path, two beam interferometers and interferometric measurement systems employ a voltage controlled variable phase retarder enabling rapid stepping of the relative phase between two interfering optical beams by suitable control of the voltage. The beams need not be laterally separated. A compact beam expander with a ball lens is preferably included. The system is compact enough to be contained in a hand-held unit. The system can be used for surface mapping, testing of optical components and detecting the motion of mechanical objects, for example. It is particularly well suited for the mapping of the skin of a live subject. An optimum fringe period and optimum illumination wavelengths for imaging skin are disclosed, enabling the topography of substantial areas of human skin to be rapidly and accurately measured, in times on the order of one-tenth of a second. Methods of conducting interferometric analysis are disclosed, as well.

Abstract: The invention consists of a method of redirecting light to improve the transmission efficiency of wedged multibeam interferometers, either individually or in cascade with other interferometers. Optical fibers are placed to direct reflected light into such positions which enable iterated transmission of this otherwise wasted light through the interferometer. The increased light coupling efficiency provided by the method makes it well suited for applications to fiber optic communication links, fiber optic Bragg sensors, ladars and lidars.