Method and system for generation of coherent subcarriers
AssigneesZTE (USA) Inc., Zte Corporation
InventorJianjun Yu
Life of this patent
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Abstract
A method and system for generating multi-subcarriers is disclosed. Re-circulating frequency shifters—based on the frequency shifting in two cascading phase modulators—are used to generate 112 subcarriers with stable architecture since there is no direct current bias in phase modulators.
Claims30
A method of generating multi-subcarrier signals using optical components, the method comprising:
- modulating a lightwave by a first phase modulator having a half-wave voltage and then by a second phase modulator, wherein the first and the second phase modulators are driven by a first and a second radio frequency signal, respectively, each radio frequency signal having a fixed frequency and amplitude, wherein the each amplitude is at least a few times greater than the half-wave voltage of the first phase modulator;
- providing a recirculation loop comprising one or more erbium-doped fiber amplifiers and an optical delay line, wherein the optical delay line is configured to generate a plurality of stable subcarriers, each stable subcarrier having a subcarrier amplitude;
- and
- using a programmable wavelength selective switch to shape each subcarrier amplitude and to suppress certain ones of the stable subcarriers.
A system for generating multi-subcarrier signals using optical components comprising:
- at least two phase modulators arranged as a cascade, each configured to modulate a lightwave;
- a recirculation loop comprising one or more erbium-doped fiber amplifiers and an optical delay line, wherein the optical delay line is configured to generate a plurality of stable subcarriers in the lightwave, each stable subcarrier having an amplitude;
- and
- a programmable wavelength selective switch configured to shape the amplitude of each subcarrier and to suppress certain subcarriers.
A computer program product for generating multi-subcarrier signals using optical components, the computer program product residing on a computer-readable medium and comprising computer-readable instructions configured to cause a computer to:
- modulate a lightwave by at least a first phase modulator having a half-wave voltage and then by a second phase modulator, wherein the first phase modulator and the second phase modulator are each driven by a radio frequency signal having a fixed frequency and an amplitude, wherein the amplitude is at least a few times greater than the half-wave voltage of the first phase modulator;
- provide a recirculation loop comprising one or more erbium-doped fiber amplifiers and an optical delay line, wherein the optical delay line is used to generate a plurality of stable subcarriers, each stable subcarrier having an amplitude;
- and
- use a programmable wavelength selective switch to shape the amplitude of each subcarrier and to suppress certain subcarriers.
Dependencies are inferred from the claim text.