Abstract: A sensitivity modulated light detection and ranging (LIDAR) system and related methods. Implementations of sensitivity modulated LIDAR systems may include a pulsed laser and a light detection system coupled with the pulsed laser through a timing system. The light detection system may include a high-bandwidth detector coupled with the timing system, at least one imaging detector coupled with the timing system, and at least one sensitivity modulator coupled with the at least one imaging detector and with the timing system.

Abstract: An imaging system. Implementations of imaging systems may include a laser light source, at least one imaging detector coupled to the laser light source, a shearing interferometer coupled to at least one imaging detector, and a timing system coupled to the at least one imaging detector and the laser light source. A ranging detector may be coupled to the laser light source and the timing system, and at least on sensitivity modulator may be coupled with the at least one imaging detector and with the timing system.

Abstract: A range-gated shearography system and related methods. Implementations of range-gated shearography systems may include a laser light source, at least one imaging detector coupled to the laser light source, a shearing interferometer coupled to the at least one imaging detector, and a ranging detector coupled to the laser light source. A method of range-gating a shearography system may include emitting laser light, determining a range interval for at least one object, receiving reflected laser light from the at least one object through a shearing interferometer from the range interval, and collecting at least one shearography image.

Abstract: A light detection and ranging (LIDAR) system uses dual detectors to provide three-dimensional imaging of underwater objects (or other objects hidden by a partially transmissive medium). One of the detectors is a low resolution, high bandwidth detector. The other is a high resolution, narrow bandwidth detector. An initial laser pulse is transmitted to known x-y coordinates of a target area. The photo signals returned from the target area from this initial pulse are directed to the low resolution, high bandwidth detector, where a preliminary determination as to the location (depth, or z coordinate) of an object in the target area is made based on the time-of-receipt of the return photo signal. A second laser pulse is then transmitted to the target area and the return photo signals from such second laser pulse are directed to the high resolution, narrow bandwidth detector.

Abstract: An optically phase-locked electronic speckle pattern interferometer mixes a local oscillator beam with a beam reflected from a target surface to create a speckle pattern at each of two separate image planes. The speckle pattern includes speckles whose intensities vary as a result of time-varying Doppler shifting of the reflected beam by movement or deformation of the target surface. The local oscillator beam is phase-locked to the Doppler signature of a lock-point speckle on one image plane. The phase-locking of the local oscillator beam to Doppler information of interest enables the interferometer to coherently detect speckle in the image plane sharing frequency, amplitude, and phase characteristics with the lock-point speckle, which supports the efficient processing of images obtained from the other image plane. The processing produces a contoured image of the target surface, with demarcation between coherently and non-coherently detected speckle.

Abstract: An infrared imaging system is presented wherein a visual image of a scene being viewed is obtained from the thermal energy radiated from said scene. The thermal energy radiated is focused onto a plurality of means for absorbing energy from the infrared radiation, specifically a two-dimensional array of gas cells with the front end being a rigid infrared transparent window, the sides being rigid, and the rear ends being flexible membranes. Infrared radiation absorbed by the cells causes changes in the thermodynamic pressure within each cell and consequent expansion of the flexible membrane on the rear end of each cylindrical cell. The deflection of these flexible membranes is monitored and measured by either a laser interferometer system or a solid state pressure sensing system. Measurement of this deflection represents the amount of infrared radiation received at each of the plurality of gas cells.

Abstract: An apparatus for providing an image of an object, a diffusive medium being ocated between the apparatus and the object, the apparatus including a coherent light source for projecting a beam of coherent light through the diffusive medium onto various light reflective parts of the object. The coherence length of the projected beam is preferably very short, and each reflective part of the object is located in one of one or more discrete viewing spaces, the depth of field of the apparatus being equal to the coherence length of the projected light. A photocathode or the like is provided for receiving light reflected back through the diffusive medium from the reflective parts, discrete incremental sections of the photo-cathode responding to received light by generating sets of light responsive signals.

Abstract: In an optical heterodyne system a first coherent light signal is received on an ordered array of light responsive elements, and a local oscillator source provides a second coherent light signal, the frequencies of the first and second coherent light signals being different. Mixing apparatus is provided to focus the second coherent light signal upon each of the light responsive elements of the array in a preselected sequence, and scanning apparatus scans the light responsive elements in the same preselected sequence to receive light responsive signals generated by the light responsive elements, each of the light responsive signals being related to the intensity of light impinging upon a different one of the light responsive elements and having a frequency equal to the difference between the frequencies of the first and second coherent light signals.

Abstract: A system for providing an image of an object from a coherent light signal transmitted from the object through a dynamic diffusive medium is provided with a planar surface receiving the signal wavefront, the received wavefront comprising an array of discrete picture elements. A local oscillator signal is mixed with each picture element in a selected order to provide light responsive signals which represent the distribution of power over frequency of each picture element, all of the frequency components of the light responsive signals being included in a first frequency range of selected bandwidth which is centered around an intermediate frequency. A narrow-band electronic filter receives each of the light responsive signals and removes all frequency components therefrom which are not included in a second, narrow, bandwidth centered around the intermediate frequency. An image of the object is provided by electronic apparatus which receives the filtered signals.

Abstract: Apparatus for overcoming the effects of back scatter and forward scatter in iewing an object through a diffusive medium includes a projector for projecting successive picosecond coherent light pulses through the medium to the object, and also includes a light receiving element for receiving light transmitted through the medium. An optical shutter is positioned in relation to the receiving element for selectively admitting light thereto. An optical path between the source and the shutter couples light of a projected pulse to open the shutter for a picosecond at a selected interval after the pulse has been projected, in order to admit light of the pulse reflected from the object to the receiving means.