Abstract: An optical repeater combines the functions of a passive star coupler and a signal regenerating amplifier. A divergence corrective device provides a means with which to more effectively utilize the optical energy radiated from a light emitting diode included in the signal regenerating amplifier. This increase in efficiency allows for the coupling of as much optical energy to each optical receiver of a multiplicity of optical receivers as would be coupled to a single optical receiver in a simple point-to-point link.

Abstract: An apparatus and method are provided for determining the extinction coefficient of an atmospheric scattering medium utilizing a single-ended optical system having a predetermined transmitter field of view and two concentrically arranged cooperating optical receivers, wherein backscattered light from near and far receiver fields of view for each of a series of transmitted light pulses is collected by the respective receivers. Optimum reception is achieved for both near and far field scatterers and the received signals are selectively processed by a processor which may include, for example, integration, summation, and differentiation steps that automatically yield extinction coefficient data under a wide range of environmental conditions without requirements of extreme apparatus stability, continuous monitoring, or calibration of the apparatus.

Abstract: A structure for electro-optic channeling of multimode light radiated from multimode fiber optic waveguides is disclosed. The light is channeled in a planar optic waveguide comprised of a high index electro-optic material to which the fiber optic waveguide is non-normal butt coupled to achieve higher in-plane collimation and greater confinement of divergent light beams with lower control voltages.

Abstract: An optical coupling apparatus having first and second optical waveguides wherein optical signals are coupled therebetween in a distributive manner. The distributive coupling provides essentially equally distributed optical signals in the secondary guide while maintaining an essentially continuous flow of light in the primary guide.

Abstract: A fingerprint optical sensor terminal is provided for use in the real time recording of an impression of a fingerprint pattern, the human finger being placed for the purpose at an input window surface of the sensor terminal. The sensor terminal provides precise angular and positional alignment of the finger and affords the immediate recognition of the presence of a finger that would produce a poor impression, permitting prompt corrective action by the operator. The sensor terminal also permits the making of an impression of a wide area of the finger, thus providing increased discrimination and accuracy of print identification with increased economy.

Abstract: An improved incoherent optical processor fingerprint identification apparatus employs a rotatable grating for inspecting the ridge orientations in a plurality of preselected finite sample areas of a fingerprint. A detector array including a plurality of detectors each related to a discrete sampled area is disposed to receive an image of the fingerprint filtered by the rotating grating. An incoherent light source and a lens and retroreflective prism assembly function in cooperation with the grating to produce an image thereof superposed on the grating itself such that minimum light is propagated to the detector array in the absence of an input fingerprint pattern whereas, in the presence of a fingerprint pattern, light is diffracted thereby to be filtered by the grating for supply to the detectors.

Abstract: A digital processor for extracting data from a binary image in which the image is divided into an array of sample areas, each sample area containing an array of binary data spaces. Patterns formed by adjacent data spaces within the sample sample represent local line orientations from which the image characteristics are determined. Sample areas linearly arrayed in the direction in which the image is scanned are simultaneously processed to extract the line orientation information contained therein.