EP0314491A2
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EP
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Polarization diversity light receiving system
Assignee: KDDI Corp
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Filing: 1988-10-28
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Granted: —
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Expires: 2008-10-28
Abstract
Abstract A polarization diversity light receiving system using base combining arranged so that the control signal for the local oscillator laser (2) is the sum of squared values of received signals.
Inventors
- 👤 Shiro Ryu
- 👤 Kiyofumi Mochizuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 19:31
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/60; H04B10/61; H04B10/614; H04B10/64
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
158 words
A polarization diversity light receiving system using baseband combining in which signal light of an arbitrary plane of polarization as a result of its propagation over an optical fiber is split (4) into orthogonal polarized wave components and detected by use of oscillation light output from a local oscillator laser (2) provided at the receiving side, the polarized wave components are detected to obtain electrical signals are combined, characterised by: intermediate frequency stabilizing means (20) which discriminates the frequency of each of the electrical signals, generates an output voltage corresponding to a variation in the frequency, and weights the output voltage to have a squared value of the electrical signal; and adding means (9b) for combining the outputs of the intermediate frequency stabilizing means; wherein a control signal, which is the sum of the squared values of the electrical signals, obtained by the adding means, is used to control the local oscillator laser (2), thereby stabilizing its frequency.
Claim 2
Dependent Claim
158 words
A polarization diversity light receiving system using baseband combining in which signal light of an arbitrary plane of polarization as a result of its propagation over an optical fiber is split (4) into orthogonal polarized wave components and detected by use of oscillation light output from a local oscillator laser (2) provided at the receiving side, the polarized wave components are detected to obtain electrical signals are combined, characterised by: intermediate frequency stabilizing means (20) which discriminates the frequency of each of the electrical signals, generates an output voltage corresponding to a variation in the frequency, and weights the output voltage to have a squared value of the electrical signal; and adding means (9b) for combining the outputs of the intermediate frequency stabilizing means; wherein a control signal, which is the sum of the squared values of the electrical signals, obtained by the adding means, is used to control the local oscillator laser (2), thereby stabilizing its frequency.
Claim 3
Dependent Claim
38 words
A polarization diversity light receiving system using baseband combining according to claim 1 in which said intermediate frequency stabilizing means (20) is provided to receive the electrical signals in addition to demodulators (8a, 8b) of the electrical signals.
Claim 4
Dependent Claim
54 words
A polarization diversity light receiving system using baseband combining according to claim 1 or 2, in which said intermediate frequency stabilizing means (20) is provided for the signal light of FSK modulation by the common use of demodulators (8a,8b) of the electrical signals and weighting circuits (6a,6b) at the outputs of the demodulators (8a,8b).
References Cited (Backward Citations)
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