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US 2003/0118352 A1Published application
Optical phase modulation
AssigneeFujitsu Network Communications, Inc.
InventorsSeemant Choudhary, Takeshi Hoshida
Life of this patent
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Abstract
An optical modulator provides for preceding of a high data rate phase modulated optical signal. According to one embodiment, the modulator includes a first phase modulator and a second phase modulator. The first phase modulator modulates an optical carrier signal according to a first data signal to generate a modulated optical signal. The second phase modulator modulates the modulated optical signal according to a time delayed version of its optical output signal. According to another embodiment, the modulator electrically precodes multiple data streams and modulates the precoded data streams using a series of phase modulators to generate a precoded optical data signal.
Claims20
An optical modulator comprising:
- a first phase modulator operable to phase modulate an optical carrier signal according to a first data stream to generate a modulated optical signal;
- and
- a second phase modulator operable to phase modulate the modulated optical signal according to a second data stream to generate an optical data signal, wherein the second data stream comprises a time-delayed version of the optical data signal.
A method for precoding optical data signals comprising:
- receiving an optical carrier signal;
- receiving a first electrical data steam;
- phase modulating the optical carrier signal according to the electrical data stream to generate a modulated optical signal;
- phase modulating the modulated optical signal according to a second electrical data stream to generate an optical data signal, wherein the second electrical data stream comprises a time-delayed version of the optical data signal.
1 more element
An optical modulator comprising:
- a first optical splitter having an optical input, a first optical output, and a second optical output;
- a first phase modulator having an optical input, an optical output, and an electrical data input, the optical input coupled to the first optical output of the first optical splitter;
- a second phase modulator having an optical input, an optical output, and an electrical data input, the optical input coupled to the optical output of the first phase modulator;
- a second optical splitter having an optical input, a first optical output, and a second optical output, the optical input coupled to the optical output of the second phase modulator;
- an optical coupler having a first optical input, a second optical input, and an optical output, the first optical input coupled to the optical output of the first optical splitter, and the second optical input coupled to the optical output of the second optical splitter;
- and
- a photodetector having an optical input and an eletrical output, the optical input coupled to the optical output of the optical coupler, and the electrical output coupled to the electrical data input of the second phase modulator.
4 more elements
An optical modulator comprising:
- means for receiving an optical carrier signal;
- means for receiving a first electrical data steam;
- means for phase modulating the optical carrier signal according to the electrical data stream to generate a modulated optical signal;
- means for phase modulating the modulated optical signal according to a second electrical data stream to generate an optical data signal, wherein the second electrical data stream comprises a time-delayed version of the optical data signal.
1 more element
An optical modulator comprising:
- a plurality of electrical precoding modules, each of the preceding modules operable to receive a data stream and to precode the data stream;
- and
- a plurality of phase modulators coupled in series, each of the phase modulators operable to receive the precoded data stream from a corresponding one of the precoding modules, to receive an optical signal from a preceding one of the phase modulators in the series, and to modulate the received optical signal according to the precoded data stream from the corresponding precoding module.
A method for preceding optical data signals comprising:
- receiving a plurality of electrical data streams all having communications at a first data rate;
- electrically preceding each of the electrical data streams;
- receiving an optical carrier signal;
- phase modulating the optical carrier signal according to each of the electrically precoded data streams to generate an optical data signal encoding information from all of the electrical data streams, the optical data signal having communications at a second data rate equal to the number of electrical data streams multiplied by the first data rate.
1 more element
An optical modulator comprising:
- means for receiving a plurality of electrical data streams all having communications at a first data rate;
- means for electrically precoding each of the electrical data streams;
- means for receiving an optical carrier signal;
- means for phase modulating the optical carrier signal according to each of the electrically precoded data streams to generate an optical data signal encoding information from all of the electrical data streams, the optical data signal having communications at a second data rate equal to the number of electrical data streams multiplied by the first data rate.
1 more element
An optical modulator comprising:
- a first precoding module having an input and an output, wherein the input receives a first electrical data stream, and the output transmits a first precoded electrical data stream;
- a second precoding module having an input and an output, wherein the input of the second precoding module receives a second electrical data stream, and the output of the second preceding module transmits a second precoded electrical data stream;
- a first phase modulator having an optical input, an optical output, and a data input coupled to the output of the first precoding module, wherein the optical input receives an optical carrier signal, the first phase modulator modulates the optical carrier signal according to data received on the data input to generate a modulated optical signal, and the optical output transmits the modulated optical signal;
- and
- a second phase modulator having an optical input coupled to the optical output of the first phase modulator, an optical output, and a data input coupled to the output of the second precoding module, wherein the second phase modulator modulates the modulated optical signal according to data received on the data input from the second precoding module to generate an optical data signal.
2 more elements
Dependencies are inferred from the claim text.