Laser satellite communication system
AssigneeThe MITRE Corporation
InventorROBERT T. CARLSON
Life of this patent
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Abstract
A laser communication system adapted for use in a satellite communication system. The satellite carries a laser communication system. The laser communication system includes a plurality of active and passive optical elements packaged in a monolithic, or single block, structure for interfacing between a focusing beam director of the satellite and laser transmitters/receivers of the laser communication system. Laser energy is directed between the beam director and the transmitters/receivers by the active and active optical elements, such laser energy passing through the monolithic structure solely as collimated light. In this way, diffraction relay elements, such as focusing lenses, and there concomitant alignment requirements, are eliminated from the monolithic structure.
Claims62
A laser communication system adapted for use in a satellite, such laser communication system comprising:
- a beam director;
- laser transmitter/receivers;
- a monolithic structure comprising a plurality of active and passive optical elements for interfacing between the beam director and the laser transmitters/receivers, laser energy being directed between the beam director and the transmitters/receivers by the active and active optical elements, such laser energy passing through the monolithic structure solely as collimated light.
The laser communication system recited in calm 8 wherein the filter protrudes beyond the second submodular unit and is provided with a surface adapted to interface, and be affixed to, a surface portion of the monolithic structure.
A method of assembling a laser communication system adapted for use in a satellite, such laser communication system comprising:
- a beam director;
- laser transmitter/receivers;
- and a monolithic structure comprising a plurality of active and passive optical elements for interfacing between the beam director and the laser transmitters/receivers, laser energy being directed between the beam director and the transmitters/receivers by the active and active optical elements, such laser energy passing through the monolithic structure solely as collimated light, such method comprising the steps of:
- forming a first submodular unit, such unit comprising one of the lasers and a properly aligned beam shaping lens;
- forming a second submodular unit, such second unit having a mounted collimating lens;
- aligning the first and second submodular units with each other to form a collimating/beam shaping module;
- and
- affixing the collimating/beam shaping module to a surface of the monolithic structure.
A laser communication system adapted for use in a satellite, such laser communication system comprising:
- a transmitting laser, responsive to electrical signals for converting such electrical signals into corresponding light signals;
- a detector adapted to receive light signals transmitted by a laser and convert such light signals into a corresponding electrical signals;
- a beam director adapted to direct light signals transmitted by the satellite to a receiver external to the satellite and to direct light signals received by the satellite from a source external to the satellite;
- and,
- a monolithic optical structure, for passing therethrough the light signals from the transmitting laser to the beam director and for passing therethrough light signals received by the beam director to the detector, such monolithic optical structure comprising a plurality of glass cubes and planar thin film bonded together and disposed to pass such light signals therethrough as only substantially collimated light.
The system recited in claim 32 includes a laser energy detector disposed to receive a small fraction of the laser energy produced by the laser transmitter passing through the opening to such detector.
A laser transmitter module, comprising:
- a first submodular unit having a laser transmitter and a beam shaping lens affixed to such laser transmitter;
- a second submodular unit having affixed thereto a collimating lens for collimating a beam produced by the laser transmitter;
- wherein the first and second submodular units are aligned with, and affixed to, each other to provide the collimating/beam shaping module.
The module recited in claim 55 wherein the first submodular unit includes a sapphire window mounted to the package.
A tracking system for tracking a source of incoming laser energy moving relative to the tracking system and directing a beam of laser energy to such source, such system comprising:
- a beam director;
- a laser transmitter
- a laser energy detector;
- a optical structure having an optic axis passing between the beam director and the laser transmitter and passing between the beam director and the laser energy detector, the incoming energy being directed by beam director and the optical system to the laser energy detector along the optic axis and such laser energy being produced by the laser transmitter being directed through the optical structure and the beam director along the optic axis to the source, the optical system directing the incoming laser energy to a position on the laser energy detector related to the angular deviation between the direction of the optic axis and the direction of the incoming laser energy;
- a computer for computing a lead angle between the present direction to the source and an expected direction to the source;
- and
- a control loop, responsive to:
- a signal produced the laser energy detector related to the position of the incoming laser energy on such detector relative to the optic axis;
- and, the computed lead angle, for tracking the source of incoming laser energy with a tracking error related to the computed lead angle and directing the optic axis along the expected direction such source.
A laser communication system adapted for use in a satellite, such laser communication system comprising:
- a beam director;
- laser transmitter
- a laser energy detector;
- a monolithic structure comprising a plurality of active and passive optical elements for interfacing between the beam director and the laser transmitter and laser energy detector, such monolithic optical structure having an optic axis passing between the beam director and the laser transmitter and passing between the beam director and the laser energy detector, incoming energy from a source of laser energy moving relative to the tracking system being directed by beam director and the optical system to the laser energy detector along the optic axis and such laser energy being produced by the laser transmitter being directed through the optical structure and the beam director along the optic axis to the source, the optical system directing the incoming laser energy to a position on the laser energy detector related to the angular deviation between the direction of the optic axis and the direction of the incoming laser energy;
- a computer for computing a lead angle between the present direction to the source and an expected direction to the source;
- and
- a control loop, responsive to:
- a signal produced the laser energy detector related to the position of the incoming laser energy on such detector relative to the optic axis;
- and, the computed lead angle, for tracking the source of incoming laser energy with a tracking error related to the computed lead angle and directing the optic axis along the expected direction such source.
Dependencies are inferred from the claim text.