Abstract:
A system includes an optical transceiver (204, 204a) configured to transmit/receive at least one optical feed (220) and a beam separator (210) configured to separate the optical feed into a plurality of optical beams (20, 20a-f), and spatially combine the optical beams into the optical beam. The system also includes a dichroic mirror (212) optically coupled to the beam separator and configured to reflect the optical beams, and allow beacon signals (224, 224a-f) to pass therethrough. A position sensitive detector (228) of the system optically couples to the dichroic mirror and is configured to sense an incidence position of each beacon signal allowed to pass through the dichroic mirror, and output a position error (230) for each optical beam based on the sensed incidence positions.
Abstract:
Verfahren zur Aufrechterhaltung der Übertragung von Daten in einem optischen Freistrahlkanal im Falle verschlechterter Übertragungseigenschaften des Freistrahlkanals, mit den folgenden Schritten : Bereitstellen von Terminals mit symmetrischer Terminalgeometrie, bei der über dieselbe Apertur längs einer gemeinsamen Strahlachse ein Sendestrahl gesendet und ein Empfangsstrahl empfangen wird, in jedem Terminal empfangsseitig erfolgendes Ermitteln der Empfangsleistung und in jedem Terminal senderseitig erfolgendes Ergreifen von Maßnahmen beim Senden von Daten in dem Fall der Verringerung der ermittelten Empfangsleistung und/oder des Unterschreitens mindestens eines vorgebaren Schwellwerts zur Aufrechterhaltung einer sicheren Datenübertragung und/oder einer Übertragung von Daten mit dem Ziel der empfangsseitigen Durchführung einer Korrektur der empfangenen Daten.
Abstract:
A communication-satellite system for providing communication services to the entire Earth is based on a plurality of satellites in low-earth-orbit (LEO). The satellites orbit the Earth in a plurality of orbits, with multiple satellites in each orbit. This orbital arrangement results in some locations on the surface of the Earth receiving redundant satellite coverage. Embodiments of the present invention can selectively and adaptively rotate the orientation of some of the satellites so as to transfer some of the redundant coverage from locations where it is not needed to locations where the redundant coverage is advantageous.
Abstract:
An electro -optical payload for free space optical communication includes: a plurality of optical beam expanders, each for receiving a respective optical signal of incoming optical signals; an optical cross-connect switch for directing respective optical input signals to respective optical output signals; an electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an electrical signal to an optical signal for inputting to the optical cross-connect switch; an optical-to-electrical conversion circuit coupled to an output of the optical cross-connect switch for converting an optical signal output from the optical cross-connect switch to an electrical signal; and an electrical regeneration circuit including a second optical-to-electrical conversion circuit coupled to an output of the optical cross-connect switch and a second electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an optical out signal of the optical cross-connect switch to an electrical signal.
Abstract:
A free space optical communication system (100) and method including: several optical beam expanders (414) for receiving incoming optical signals from ground sites and neighboring satellites; several optical preamplifiers (412) for preamplifying the received optical signals; one or more optical main amplifiers (404) for amplifying the preamplified optical signals; and an optical switch (408) for directing respective amplified optical signals to respective destinations via a respective optical beam expander. The respective amplified optical signals are inputted to a respective optical beam expander (414) for transmission to said respective destinations, as outgoing optical signals.
Abstract:
Un terminal de communication optique (102) qui est adapté pour réaliser des communications sur une distance supérieure à 10 000 km comprend un système d'émission-réception de signaux laser (10) et un système de pointage unique (20). Le pointage est réalisé pendant une étape de poursuite en commandant deux moteurs (21 ) du système de pointage à partir de signaux représentatifs d'une déviation d'un faisceau laser reçu. Les rotations des moteurs annulent sensiblement la déviation. Dans un premier mode de réalisation, un filtrage qui est réalisé sur les signaux de déviation permet de compenser efficacement des perturbations de faible fréquence causées par les moteurs. Dans un second mode de réalisation, des perturbations produites par le fonctionnement du système de pointage sont compensées lors de la commande des moteurs.
Abstract:
An optical transmitter includes a modulator, a dispersion adjustment module, and an optical amplifier. The optical transmitter is configured to transmit optical pulses over a free-space optical communication channel. The modulator is configured to produce an optical carrier that is amplitude and/or phase modulated by data. The dispersion adjustment module is connected between the modulator and the amplifier and is configured to substantially change temporal widths of optical pulses received from the modulator by changing dispersions of the received optical pulses.