Method of aligning transmit and receive beam for a free-space optical communication system
AssigneeX Development LLC
InventorsNam-hyong Kim, Robert Todd Belt
Life of this patent
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Abstract
A fully-passive optical system creates a counter-propagating reference beam, which may be used to evaluate a misalignment between a receive beam, a transmit beam, and a tracking beam. The system can be mated to a motorized tip-tilt stage, and can measure power of received signals and automatically adjust the tip-tilt stage in response. Thus, the system would always maintain bore-sight with the received beam regardless of mechanical shift over time.
Claims18
A reference system for testing an optical communication system, the reference system comprising:
- a receiver adapted to receive an optical beam from the optical communication system;
- a transmitter adapted to, simultaneously with the receiving of the optical beam, transmit a reference optical beam;
- and
- a movable stage on which the receiver and the transmitter are attached, the movable stage being adapted to enable at least one of lateral or vertical movement of the reference system, adjust roll, pitch, or yaw of the receiver and the transmitter, and hold the receiver and the transmitter in a position where the reference optical beam is co-linear with the received optical beam along an entire path between the optical communication system and the receiver.
A reference system for calibrating an optical communication system under test, the reference system comprising:
- a receiver adapted to receive an optical signal from the optical communication system under test;
- a receiver tip in optical communication with the receiver through optics arranged to redirect the received optical signal to the receiver tip;
- a power meter in optical communication with the receiver tip, the power meter configured to determine a power level of the received optical signal;
- an optical signal source adapted to generate a reference beam, wherein the power level is used to verify alignment of the reference beam and the received optical signal;
- a transmitter adapted to transmit the generated reference beam while the receiver continuously receives optical signals from the optical communication system under test;
- and
- a movable stage adapted to enable at least one of lateral or vertical movement of the reference system, adjust roll, pitch, or yaw of the receiver and the transmitter, and hold the receiver and the transmitter in a position where the reference beam is co-linear with the received optical signal along an entire path between the optical communication system and the receiver.
A method for calibrating a free space optical communication system, the method comprising:
- receiving, at a reference system, an optical beam transmitted from the optical communication system at a remote position with respect to the reference system;
- generating, at the reference system, a reference optical beam;
- determining whether the reference optical beam is colinear with the received optical beam;
- when the reference optical beam is not colinear with the received optical beam, adjusting a roll, pitch, or yaw of the reference system by controlling a movable stage on which the reference system is mounted until the reference optical beam is colinear with the received optical beam, wherein the movable stage is adapted to enable at least one of lateral or vertical movement of the reference system;
- and
- recording, at the optical communication system, a position of the reference optical beam when the reference optical beam is colinear with the received optical beam.
Dependencies are inferred from the claim text.