Abstract: The present invention provides a method and apparatus for free-space optical communication. The method comprises the steps of receiving a receive optical beam through a narrow field of view, determining a receive power level, shifting an alignment, maximizing the receive power, and transmitting a transmit optical beam along the alignment, wherein the narrow field of view is less than a divergence of the transmit optical beam. The narrow field of view can be a narrow region of a multi-region field of view. The apparatus comprises an optical beam transmitter configured to generate a narrow diverging transmit beam, a narrow field of view optical receiver, wherein the field of view is less than the divergence of the transmit beam, and a controller configured to determine a power level of a receive beam and to determine adjustments to a direction of transmission maximizing receive power.

Abstract: The present invention provides an apparatus and method for tracking alignment between transceivers for free-space optical communication. The method comprises the steps of receiving a received narrow optical beam, determining an angle at which the optical beam is received, quickly shifting an alignment such that the alignment minimizes the angle, and directing a narrow transmit optical beam along the alignment. The method further shifting the alignment through at least a portion of a search pattern searching for the receive beam. The apparatus provides free-space optical communication, comprises an optical beam detector configured to receive a received narrow tracking beam, an optical beam source configured to generate a narrow transmit tracking beam, and a controller configured to determine an angle of reception of the receive beam and to control a direction of transmission of the transmit beam such that the angle is minimized.

Abstract: The present invention provides a method and apparatus for free-space optical communication. The method comprises the steps of receiving a receive optical beam through a narrow field of view, determining a receive power level, shifting an alignment, maximizing the receive power, and transmitting a transmit optical beam along the alignment, wherein the narrow field of view is less than a divergence of the transmit optical beam. The narrow field of view can be a narrow region of a multi-region field of view. The apparatus comprises an optical beam transmitter configured to generate a narrow diverging transmit beam, a narrow field of view optical receiver, wherein the field of view is less than the divergence of the transmit beam, and a controller configured to determine a power level of a receive beam and to determine adjustments to a direction of transmission maximizing receive power.

Abstract: The present invention provides an apparatus and method for free space optical communication. The apparatus and method provide a free-space optical communication. The apparatus can include a link head configured to provide optical communication, a microroom cover positioned about and encasing the link head and a flexure support. The flexure support is secured at a first end with the microroom cover and extends away from the microroom cover, and is further secured at a second end with a structure, wherein the flexure support is configured to flex from a first position when a force is applied to the microroom cover. The present invention optically aligns a first and second free-space optical communication apparatuses. When a force is received on the first communication apparatus a portion of the first apparatus tilts to maintain the optical alignment between the first and second communication apparatuses.

Abstract: The present invention provides a method and apparatus for free space optical communication. The method and apparatus transmit a large diameter optical signal across a free space link to over fill a plurality of receive objectives. Each of receive objectives focus the portions of the impinging optical signal into a respective fiber optic core, where the fiber optic is a single mode, multi-mode, small multi-mode or other type of fiber. The signals in each of the respective fibers are combined to obtain a single received signal. The apparatus and method further provide wavelength conversion, power adjustment, and further maintains alignment between cooperating transceivers.

Abstract: Free-space optical transceivers employ wavelength conversion from a fiber interface wavelength &lgr;fiber to a free-space transform wavelength &lgr;fs and back again to overcome a broad range of environmental impacts to the free-space optical signal, such as fog. The wavelength conversions may be performed all-optically without the need for electro-optical conversion, or the wavelength conversions may be performed using electro-optical conversion. The performance of the chosen value for the free-space transform wavelength &lgr;fs may be monitored and a feedback control system used to dynamically adjust the value for &lgr;fs until the optimum value for the given atmospheric conditions is achieved. Cooperating transceivers can be informed of a newly selected value for &lgr;fs via a direct, out-of-band control communications channel, or cooperating transceivers can determine the appropriate wavelength transform amount to be applied by an adaptive wavelength selection determination.

Abstract: A telescope with a spherical primary mirror and movable lightweight secondary assembly which includes an optical, imaging component and at least one location component both of which components are attached to a pivot arm. The location component can be a microwave, radio frequency or acoustic location component. The optical component of this secondary assembly reflects a portion of focused light radiation from the primary mirror back to the primary mirror and thence through a hole in the secondary mirror to a coude' optics device at the center of curvature of the primary mirror. The coude' optics device in turn reflects the focused light radiation to an imaging detector housed in the outer structure of the telescope. A preferred embodiment of the present invention combines all three of these location systems with the optical imaging component.

Abstract: A telescope with a spherical primary mirror and a movable secondary optical element which is positioned at various locations near the focal plane of the primary mirror and directs a portion of the focused radiation to a coude optics device at the center of curvature of the primary mirror. The coude optics device reflects the focused radiation to a detector. In a preferred embodiment of this invention a field of several degrees can be scanned very rapidly while viewing much smaller object fields.