Coherent gated receiver
View Patent ↗The present invention is directed to a coherent gated receiver. The receiver includes a decoder operable to receive an optical signal and generate a decoded optical signal, the decoder comprises a demultiplexer operable to spatially distribute the optical signal, a phase mask operable to decode the spatially distributed optical signal, and a multiplexer operable to combine the decoded spatially distributed optical signal. The receiver also includes a laser source operable to provide a pulse signal, a combiner coupled to the laser source and the decoder operable to combine the decoded optical signal and the pulse signal, and a detector operable to detect an output from the combiner.
1. A coherent gated receiver for optical code division multiple access (OCDMA) comprising:
a decoder operable to receive an optical signal comprising multiple encoded channels and generate a decoded optical signal, the decoder comprises a an optical demultiplexer operable to spatially distribute the spectral content of the received optical signal, a phase mask operable to decode the spatially distributed optical signal, and a multiplexer operable to combine the decoded spatially distributed optical signal;
a laser source operable to provide a pulse signal with phase-locked frequency components matching frequency components in the received signal;
a combiner coupled to the laser source and the decoder operable to combine the decoded optical signal and the pulse signal; and
a detector operable to detect an output from the combiner.
2. The coherent gated receiver according to claim 1 , wherein the optical signal is spatially distributed by frequency.
3. The coherent gated receiver according to claim 1 , wherein the laser source is a mode locked laser with phase-locked frequency components matching frequency components in the received signal.
4. The coherent gated receiver according to claim 1 , further comprising a second detector operable to detect an output from the combiner.
5. The coherent gated receiver according to claim 4 , wherein the output of the detector and the second detector are subtracted from each other to generate a signal.
6. The coherent gated receiver according to claim 1 , wherein the combiner is 2×2 combiner.
7. A coherent gated receiver comprising:
a laser source operable to provide a pulsed signal with phase-locked frequency components matching frequency components in the transmitted signal;
an encoder coupled to the laser source and operable to encode the pulse signal, the encoder comprises, a demultiplexer operable to spatially distribute the pulse signal, a phase mask operable to encode the spatially distributed pulse signal, and a multiplexer operable to combine the encoded spatially distributed pulse signal;
a combiner operable to combine the encoded pulse signal and an optical signal; and
a detector operable to detect an output from the combiner.
8. The coherent gated receiver according to claim 7 , wherein the pulse signal is spatially distributed by frequency.
9. The coherent gated receiver according to claim 7 , wherein the laser source is a mode locked laser with phase-locked frequency components matching those in the received signal.
10. The coherent gated receiver according to claim 7 , further comprising a second detector operable to detect an output from the combiner.
11. The coherent gated receiver according to claim 10 , wherein the output of the detector and the second detector are subtracted from each other to generate an signal.
12. The coherent gated receiver according to claim 7 , wherein the combiner is 2×2 combiner.