Abstract: A system and method are provided for receiving light that has traveled from an optical source through an atmosphere along a distance. The system includes: a receiver lens system having an aperture and being arranged to receive the light from the optical source; a beam splitter; an imaging lens; an image processing component; a photodetector system; and a refractive index structure parameter component. The photodetector system outputs data associated with averaged scintillation data of the aperture. The image processing component generates a normalized covariance curve based on a first portion of the received light. The refractive index structure parameter component generates a refractive index structure parameter, Cn2, of the atmosphere along the distance based on the data associated with averaged scintillation data of the aperture and the normalized covariance curve.

Abstract: A method for cooling a satellite system comprising configuring a plurality of fins to absorb and emit thermal radiation, wherein the ratio of absorptivity/emissivity is less than one; mechanically coupling the plurality of fins to the outside surface of a satellite, wherein the angle of the plurality of fins can be adjusted and controlled such that they can be stowed against the surface of the satellite or deployed; deploying the fins as necessary to expel heat from the satellite.

Abstract: An optical signal passing through an atmosphere is received by a liquid lens. Distortion of the received optical signal caused by turbulence in the atmospheric is measured. Adjustments of either or both of the focal length and the focal position of the liquid lens needed to correct for the distortion are determined. Either or both of the focal length and the focal position of the liquid lens are adjusted to correct for the distortion.

Abstract: A retroreflective optical system for creating a passive optical tag in an absence of electrical power, involving: a retroreflector having a surface and a retroreflective element disposed in relation to the surface, the retroreflective element configured to: passively impart a unique signature in relation to incoming light by using at least one of spectral filtration and color filtration, whereby a plasmonic response is effectible; and reflect outgoing light having the unique signature; and an optical device having an input aperture, the optical device disposed at a distance from the retroreflector and configured to transmit the incoming light and the outgoing light.

Abstract: A system and method are provided for receiving light that has traveled from an optical source through an atmosphere along a distance. The system includes: a receiver lens system having an aperture and being arranged to receive the light from the optical source; a beam splitter; an imaging lens; an image processing component; a photodetector system; and a refractive index structure parameter component. The photodetector system outputs data associated with averaged scintillation data of the aperture. The image processing component generates a normalized covariance curve based on a first portion of the received light. The refractive index structure parameter component generates a refractive index structure parameter, Cn2, of the atmosphere along the distance based on the data associated with averaged scintillation data of the aperture and the normalized covariance curve.

Abstract: A system and method involve using a first laser to generate a laser-induced plasma filament within an optically-transparent medium, using a second laser to generate a communication signal, and using a signal combiner positioned within the path of both the first laser and the second laser to direct the communication signal through the laser-induced plasma filament to a receiver located within the optically-transparent medium.

Abstract: Methods for characterizing atmospheric turbulence along an optical path from a laser transmitter to a laser receiver can include the steps of counting the number of laser speckles at the receiver imaging plane, and then finding Fried's parameter r0 using the counting result to characterize the turbulence along the path. Before counting speckles, images at the receiver image plane can be preprocessed by capturing the images. The captured images at the image plane can then be blurred and a threshold can be chosen so that only certain pixels in the image are further processed. The thresholding can be via Otsu's methods or via variants of a Gaussian fit. Kostelec's method can then be used to count speckles in the portions of the image that have made it through the thresholding step. Other counting methods could be used. Fried's can then be found using the speckle count.

Abstract: A system comprises a tracking electromagnetic beam generator, a retro-reflecting device, a signal generator, a communication electromagnetic beam generator and a receiver. The tracking electromagnetic beam generator transmits a tracking electromagnetic beam. The retro-reflecting device reflects the tracking electromagnetic beam toward the tracking electromagnetic beam generator. The signal generator generates a communication signal. The communication electromagnetic beam generator transmits a communication electromagnetic beam, based on the communication signal, to the retro-reflecting device. The receiver receives a portion of the communication electromagnetic beam as reflected from the retro-reflecting device.

Abstract: A system comprises a tracking electromagnetic beam generator, a retro-reflecting device, a signal generator, a communication electromagnetic beam generator and a receiver. The tracking electromagnetic beam generator transmits a tracking electromagnetic beam. The retro-reflecting device reflects the tracking electromagnetic beam toward the tracking electromagnetic beam generator. The signal generator generates a communication signal. The communication electromagnetic beam generator transmits a communication electromagnetic beam, based on the communication signal, to the retro-reflecting device. The receiver receives a portion of the communication electromagnetic beam as reflected from the retro-reflecting device.

Abstract: Methods for characterizing atmospheric turbulence along an optical path from a laser transmitter to a laser receiver can include the steps of counting the number of laser speckles at the receiver imaging plane, and then finding Fried's parameter r0 using the counting result to characterize the turbulence along the path. Before counting speckles, images at the receiver image plane can be preprocessed by capturing the images. The captured images at the image plane can then be blurred and a threshold can be chosen so that only certain pixels in the image are further processed. The thresholding can be via Otsu's methods or via variants of a Gaussian fit. Kostelec's method can then be used to count speckles in the portions of the image that have made it through the thresholding step. Other counting methods could be used. Fried's can then be found using the speckle count.

Abstract: A method for isolating an optical signal comprising the following steps: receiving the optical signal from a transmitter with a receiver after the optical signal has propagated through a turbulent medium separating the transmitter from the receiver; splitting the received signal into first and second signals; filtering the first signal with an in-band spectral filter to create an in-band signal centered at an operating wavelength of the transmitter; filtering the second signal with an out-of-band spectral filter to create an out-of-band signal slightly out-of-band with respect to the operating wavelength of the transmitter; and subtracting the out-of-band signal from the in-band signal with a balanced detector in order to generate an output signal, whereby the output signal is a real-time representation of the intensity of the optical signal without background intensity.

Abstract: A system and method involve using a first laser to generate a laser-induced plasma filament within an optically-transparent medium, using a second laser to generate a communication signal, and using a signal combiner positioned within the path of both the first laser and the second laser to direct the communication signal through the laser-induced plasma filament to a receiver located within the optically-transparent medium.

Abstract: A system and method involve detecting a modulated optical signal from an atmospheric propagation channel, wherein the modulated optical signal comprises an optical signal from an optical source modulated with a periodic signal at a modulation frequency greater than the bandwidth of the turbulence within the atmospheric propagation channel, and converting the detected modulated optical signal into a digitized electrical signal. The method also includes determining the root mean square signal power of an AC component of the digitized electrical signal at the modulation frequency. The method further includes determining the power spectral density of the digitized electrical signal, determining the magnitude of the peak component at the modulation frequency, and determining the effective optical depth of the atmospheric propagation channel using the magnitude of the peak component at the modulation frequency.

Abstract: A system and method involve detecting a modulated optical signal from an atmospheric propagation channel, wherein the modulated optical signal comprises an optical signal from an optical source modulated with a periodic signal at a modulation frequency greater than the bandwidth of the turbulence within the atmospheric propagation channel, and converting the detected modulated optical signal into a digitized electrical signal. The method also includes determining the root mean square signal power of an AC component of the digitized electrical signal at the modulation frequency. The method further includes determining the power spectral density of the digitized electrical signal, determining the magnitude of the peak component at the modulation frequency, and determining the effective optical depth of the atmospheric propagation channel using the magnitude of the peak component at the modulation frequency.