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US Patent 6671056 - Method and system for optical spectrum analysis with a depolarized local oscillator signal
US Patent Issued on December 30, 2003
Estimated Patent Expiration Date:
January 11, 2021Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
Estimated Patent Expiration Date:
January 11, 2021Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.AbstractAn optical spectrum analyzer involves a swept local oscillator signal that is depolarized before the swept local oscillator signal is combined with an input signal. An embodiment of a system for optical spectrum analysis includes a depolarizer, an optical coupler, and a heterodyne receiver. The depolarizer has an input to receive a swept local oscillator signal and an output for outputting a depolarized swept local oscillator signal. The optical coupler has a first input and a second input, the first input receiving an input signal, the second input being optically connected to the depolarizer to receive the depolarized swept local oscillator signal. The optical coupler also has an output for outputting a combined optical signal that includes the input signal and the depolarized swept local oscillator signal. The heterodyne receiver has an input for receiving the combined optical signal from the optical coupler and an output for outputting an electrical signal representative of the combined optical signal. In an embodiment, the swept local oscillator signal is depolarized such that the average polarization state of the swept local oscillator signal contains no preferential polarization state. | InventorApplicationNo. 09/759004 filed on 01/11/2001US Classes:356/484, Having light beams of different frequencies (e.g., heterodyning)356/477Using fiber or waveguide interferometerField of Search356/477Using fiber or waveguide interferometerExaminersPrimary: Turner, Samuel A.Assistant: Connolly, Patrick US Patent References4903342, Optical heterodyne homodyne detection apparatusIssued on: 02/20/1990 Inventor: Yamazaki5202745, Polarization independent optical coherence-domain reflectometry Issued on: 04/13/1993 Inventor: Sorin, et al.5903393, Optical-hybrid etalons for simultaneous phase- and polarization-diversity operations Issued on: 05/11/1999 Inventor: Kalibjian6043921Fading-free optical phase rate receiver Issued on: 03/28/2000 Inventor: Payton International ClassesG01J 9/04 (20060101)G01J 9/00 (20060101) |
