Optical heterodyne homodyne detection apparatus
Patent 4903342 Issued on February 20, 1990. Estimated Expiration Date: 
October 27, 2008. Estimated 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.
October 27, 2008. Estimated 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.InventorAssigneeApplicationNo. 263216 filed on 10/27/1988US Classes:398/204, Heterodyne398/1, FAULT RECOVERY398/203, Homodyne398/205Including polarizationExaminersPrimary: Griffin, Robert L.Assistant: Van Beek, L. Attorney, Agent or FirmForeign Patent References
International ClassH04B 009/00Foreign Application Priority Data1987-10-27 JPAbstractIn an optical heterodyne homodyne detection apparatus, signal light and local oscillation light are combined, and the combined light is received in an optical detector to produce intermediate frequency signal which is then demodulated thereby producing base band signals. The frequency sweep of the intermediate frequency signal is performed so that the frequency of the intermediate frequency signal becomes a predetermined value. During the frequency sweep, at least one polarization of the signal light and the intermediate frequency signal is scrambled, and is stopped when the frequency becomes the predetermined value. Thereafter, polarizations of the signal light and the local oscillation light are coincided with each other in accordance with the polarization angle control. | |
