Abstract: A process and device are disclosed to measure angular speeds. In order to determine the Sagnac phase from the output signal of a fiber optic annular interferometer, without the need for costly circuits for regulating a phase modulator that acts on the interference light and for regulating the intensity of the light, the Sagnac phase shift .phi. is deduced from the amplitudes (A.sub..nu.-1, A.sub..nu., A.sub..nu.+1) of three spectral lines of the interference light that is emitted by the interferometer.

Abstract: Holographic optical elements are utilized for discriminating between monochromatic, coherent radiation and broadband, noncoherent radiation in passive coherent radiation detection systems such as aircraft warning systems and submarine laser communication systems. Coherent laser light can possess an extremely high energy density, directivity, (i.e., collimation), and a very narrow wavelength band when compared to natural or man-made, broadband white light sources. The concentration of laser light energy by a holographic optical element at the detector stage is a consequence of its special characteristics. Moreover, equally important, the diffracted light distribution in the neighborhood of the detector possesses a unique, bright geometric pattern not readily obtained with noncoherent sources. This geometric pattern is used as a laser wavelength detector for determination of the incident angular direction of the laser beam, as well as a coherent/noncoherent light discriminator.

Abstract: A method of profiling a rough surface of an object includes moving the object along a z axis so that a highest point of the rough surface is optically aligned with and outside of the focus range of a solid-state imaging array. An interferogram of the rough surface then is produced by means of a two beam interferometer. The solid-state imaging array is operated to scan the rough surface along x and y axes to produce intensity data for each pixel of the solid-state imaging array for a plurality of frames each shifted from the other by a preselected phase difference. The modulation for each pixel is computed from the intensity data. The most recently computed modulation of each pixel is compared with a stored prior value of modulation of that pixel. The prior value is replaced with the most recently computed value if the most recently computed value is greater.