Method and device for obtaining a desired phase of optical characteristic of a fabry-perot etalon
AssigneeLucent Technologies Inc.
InventorsDavid A. Ackerman, Thomas L. Koch
Life of this patent
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Abstract
A method and device for obtaining a desired phase of optical characteristic of a Fabry-Perot (FP) etalon using multiple optical detectors which, while passively aligned at various positions relative to an incident light beam, detect different phases of light signal emerging from the FP etalon. An FP etalon and optical detector array constructed in accordance with the present invention may be used as a frequency discriminator in an optical system where the FP etalon optical characteristic is required to have a particular phase.
Claims35
A method of controlling the frequency of an optical source that defines an optical axis and that radiates an optical signal, said method comprising the steps of:
- (a) providing a Fabry-Perot etalon along the optical axis, the etalon having a substantially planar incident surface upon which the optical signal impinges, and a substantially planar exit surface from which an exit optical signal emerges;
- (b) providing a plurality of optical detectors at the exit surface of the etalon at various positions relative to the optical axis;
- (c) detecting, by each of the plurality of optical detectors, an exit optical signal having a different phase characteristic;
- and
- (d) selecting an optical detector that detects a desired phase characteristic of the optical signal.
A method of controlling the frequency of an optical source that defines an optical axis and that radiates an optical signal, said method comprising the steps of:
- (a) providing a Fabry-Perot etalon along the optical axis, the etalon having a substantially planar incident surface upon which the optical signal impinges, and a substantially planar exit surface from which an exit optical signal emerges;
- (b) placing a plurality of optical detectors at the exit surface of the Fabry-Perot etalon;
- (c) determining the spectra each of the plurality of detectors will detect as a function of wavelength;
- (d) detecting, by each of the plurality of optical detectors, an exit optical signal having a different phase characteristic;
- and
- (e) selecting an optical detector that detects a desired phase characteristic of the optical signal.
A closed-loop frequency discrimination system comprising:
- an optical source for radiating an optical signal at a predetermined frequency along an optical axis;
- a frequency discriminator for detecting the optical signal radiated by said optical source, said frequency discriminator comprising a Fabry-Perot etalon having a substantially planar incident surface upon which the optical signal impinges and a substantially planar exit surface from which an exit optical signal emerges, and an optical detector array having a plurality of optical detectors arranged at said exit surface of said etalon at various positions with respect to the optical axis, each of said plurality of optical detectors detecting a different phase characteristic of the exit optical signal;
- and
- a controller connected to said optical source to control the frequency of the optical signal radiated thereby.
An open-loop optical transmission system comprising:
- an optical source for radiating an optical signal at a predetermined frequency along an optical axis;
- a frequency discriminator for detecting the optical signal radiated by said optical source, said frequency discriminator comprising a Fabry-Perot etalon having a substantially planar incident surface upon which the optical signal impinges and a substantially planar exit surface from which an exit optical signal emerges, and an optical detector array having a plurality of optical detectors arranged at said exit surface of said etalon at various positions with respect to the optical axis, each of said plurality of optical detectors detecting a different phase characteristic of the exit optical signal;
- and
- a detector connected to said frequency discriminator for detecting the optical signal at the predetermined frequency.
A method of detecting a predetermined frequency in a multi-frequency optical signal radiated by an optical source along an optical axis, said method comprising the steps of:
- (a) receiving the multi-frequency optical signal by a Fabry-Perot etalon having a substantially planar incident surface upon which the multi-frequency optical signal impinges, and a substantially planar exit surface from which a single frequency optical signal emerges;
- (b) providing a plurality of optical detectors at the exit surface of the etalon;
- (c) detecting, by each of the plurality of optical detectors, an exit optical signal at the predetermined frequency having a different phase characteristic;
- and
- (d) selecting an optical detector that detects a desired phase characteristic of the optical signal.
A method of obtaining a desired phase of optical characteristic of a Fabry-Perot etalon having a substantially planar incident surface and a substantially planar exit surface, said method comprising the steps of:
- (a) providing an optical array having a plurality of optical detectors at the exit surface of the etalon;
- (b) directing an optical signal along an optical axis toward the incident surface of the etalon;
- (c) detecting, by each of the plurality of optical detectors, an exit optical signal having a different phase of optical characteristic;
- and
- (d) selecting an optical detector that detects the desired phase of optical characteristic of the optical signal.
Dependencies are inferred from the claim text.