Two-way optical communications system
First Claim
1. An optical communications system comprising a transceiver arranged to provide two-way communication over an optical communications channel, the transceiver comprising:
- a semiconductor light source,an optical signal-to-electrical signal detector, andan electrical signal frequency selective filter,the semiconductor light source and the detector being optically and physically aligned with each other and with the optical communications channel such that light from the communications channel passes through the light source and onto the detector together with light generated by the source which also acts on the detector,the semiconductor light source providing optical signals for transmission via the optical communications channel, andthe detector detecting optical signals both as transmitted by the source and as received via the optical communications channel through the source and converting said optical signals into electrical signals,wherein means are provided for modulating the output of the semiconductor light source with an RF carrier having a first frequency, andwherein said electrical signals are passed through the filter which filters out signals at said first frequency.
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Accused Products
Abstract
An optical communications system comprises a transceiver arranged to provide two-way communication over an optical communications channel (3). The transceiver comprises a semiconductor light source (4) and a detector (5). The semiconductor light source (4) provides optical signals for transmission via the optical communications channel (3), and the detector (5) detects optical signals received via the optical communications channel and converts said optical signals into electrical signals. Means (2)a, (2)b) are provided for modulating the output of the semiconductor light source (4) with an RF carrier having a first frequency. Said electrical signals are passed through filter (8) adapted to filter out signals at said first frequency.
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Citations
12 Claims
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1. An optical communications system comprising a transceiver arranged to provide two-way communication over an optical communications channel, the transceiver comprising:
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a semiconductor light source, an optical signal-to-electrical signal detector, and an electrical signal frequency selective filter, the semiconductor light source and the detector being optically and physically aligned with each other and with the optical communications channel such that light from the communications channel passes through the light source and onto the detector together with light generated by the source which also acts on the detector, the semiconductor light source providing optical signals for transmission via the optical communications channel, and the detector detecting optical signals both as transmitted by the source and as received via the optical communications channel through the source and converting said optical signals into electrical signals, wherein means are provided for modulating the output of the semiconductor light source with an RF carrier having a first frequency, and wherein said electrical signals are passed through the filter which filters out signals at said first frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An optical signal transceiver system including a first transceiver comprising:
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an optical fibre input/output port connectable to receive optical signals having information modulated on a carrier frequency f2; an optical signal source optically coupled to said input/output port and electrically modulated with first information on a first carrier frequency f1 for transmitting via said fibre optical signals having information modulated on said carrier frequency f1; an optical signal detector optically coupled to said input/output port through said optical signal source so as to detect both signals generated by the source and signals received via the optical fibre input/output port through the source and providing composite electrical signals including both (a) said first information modulated on said first carrier frequency f1 and (b) second information received via said input/output port modulated on a second carrier frequency f2; and an electrical signal frequency-selective filter coupled to receive said composite electrical signals and to output frequency-filtered signals representing said second information modulated on said second carrier frequency f2 while substantially rejecting and not outputting signals representing said first information modulated on said first carrier frequency f1. - View Dependent Claims (10, 11)
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12. An optical signal transceiver system having plural transceivers optically coupled via an optical fibre, each of said transceivers comprising:
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an optical fibre input/output port for optical coupling to said optical fibre; an optical signal source optically coupled to said input/output port and electrically modulated with information on a carrier frequency; an optical signal detector optically coupled to said input/output port through said optical signal source so as to detect both signals generated by the source and signals received via the optical fibre input/output port through the source and providing composite electrical signals representing different information modulated on different respective carrier frequencies representing information both being received and being transmitted; and a frequency-selective electrical signal filter coupled to receive said composite electrical signals.
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Specification