Phase-insensitive recovery of clock pulses of wavelength division multiplexed optical signals
First Claim
1. An optically-pumped mode-locked fiber ring laser for optical clock recovery of multiple wavelength division multiplexed optical signals for mode-locking a plurality of outputs of the laser as a plurality of recovered clocks for a plurality of the multiple wavelength division multiplexed optical signals, the laser comprising:
- a laser cavity having a cavity length corresponding to an integer multiple of bit periods of at least one of the multiplexed optical signals for receiving a pre-amplified version of the plurality of wavelength division multiplexed optical signals to provide gain modulation through a phase-insensitive parametric amplification and recirculating a proportion of the output from the laser cavity back through the laser cavity for spatially mode-locking the output of the laser cavity as a recovered clock whereby the recovered optical clock each having a periodic train of optical pulses with a repetition rate corresponding to the clock rate of the corresponding multiplexed optical signal is generated by mode-locking of the optically-pumped laser produced by a spatial modulation of the phase-insensitive parametric gain produced by the pulsed nature of the wavelength division multiplexed optical signals;
a nonlinear gain medium disposed in the cavity, the medium having a sufficiently large dispersion at all of the wavelengths corresponding to the multiple wavelength multiplexed optical signals for minimizing four-wave mixing crosstalk among the multiple wavelength multiplexed optical signals, among the recovered clocks, and between the plurality of multiple wavelength multiplexed optical signals and the recovered clocks, the gain medium pumped by the plurality of pre-amplified multiplexed optical signals to provide efficient gain modulation through the phase-insensitive parametric amplification at a plurality of narrow wavelength bands, each of the plurality of narrow wavelength bands immediately adjacent to a wavelength of a corresponding optical signal and each of the plurality of narrow wavelength bands including a corresponding recovered optical clock wavelength, and each of the corresponding optical signals copropagating in the laser cavity through the nonlinear gain medium with the recovered optical clocks;
an optical amplifier having an inhomogenously broadened gain for amplifying the plurality of recovered clocks for compensating a portion of the cavity loss at all wavelengths of the plurality of recovered clocks; and
a wavelength selector for passing the light at the plurality of wavelengths of the recovered clocks for recirculation in the laser cavity and preventing the light from the multiple wavelength division multiplexed optical signals and a plurality of idler waves generated by four wave mixing between the multiple wavelength division multiplexed optical signals and recovered optical clocks from recirculating in the laser cavity.
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Accused Products
Abstract
An optically-pumped mode-locked fiber ring laser for optical clock recovery of multiple wavelength division multiplexed optical signals actively mode-locks a plurality of outputs of the laser as a plurality of recovered clocks for a plurality of the multiple wavelength division multiplexed optical signals. The laser cavity has a cavity length corresponding to an integer multiple of bit periods of at least one of the multiplexed optical signals for receiving a pre-amplified version of the plurality of wavelength division multiplexed optical signals to provide gain modulation through a phase-insensitive parametric amplification and recirculating a proportion of the output from the laser cavity back through the laser cavity for spatially mode-locking the output of the laser cavity as a recovered clock.
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Citations
20 Claims
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1. An optically-pumped mode-locked fiber ring laser for optical clock recovery of multiple wavelength division multiplexed optical signals for mode-locking a plurality of outputs of the laser as a plurality of recovered clocks for a plurality of the multiple wavelength division multiplexed optical signals, the laser comprising:
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a laser cavity having a cavity length corresponding to an integer multiple of bit periods of at least one of the multiplexed optical signals for receiving a pre-amplified version of the plurality of wavelength division multiplexed optical signals to provide gain modulation through a phase-insensitive parametric amplification and recirculating a proportion of the output from the laser cavity back through the laser cavity for spatially mode-locking the output of the laser cavity as a recovered clock whereby the recovered optical clock each having a periodic train of optical pulses with a repetition rate corresponding to the clock rate of the corresponding multiplexed optical signal is generated by mode-locking of the optically-pumped laser produced by a spatial modulation of the phase-insensitive parametric gain produced by the pulsed nature of the wavelength division multiplexed optical signals;
a nonlinear gain medium disposed in the cavity, the medium having a sufficiently large dispersion at all of the wavelengths corresponding to the multiple wavelength multiplexed optical signals for minimizing four-wave mixing crosstalk among the multiple wavelength multiplexed optical signals, among the recovered clocks, and between the plurality of multiple wavelength multiplexed optical signals and the recovered clocks, the gain medium pumped by the plurality of pre-amplified multiplexed optical signals to provide efficient gain modulation through the phase-insensitive parametric amplification at a plurality of narrow wavelength bands, each of the plurality of narrow wavelength bands immediately adjacent to a wavelength of a corresponding optical signal and each of the plurality of narrow wavelength bands including a corresponding recovered optical clock wavelength, and each of the corresponding optical signals copropagating in the laser cavity through the nonlinear gain medium with the recovered optical clocks;
an optical amplifier having an inhomogenously broadened gain for amplifying the plurality of recovered clocks for compensating a portion of the cavity loss at all wavelengths of the plurality of recovered clocks; and
a wavelength selector for passing the light at the plurality of wavelengths of the recovered clocks for recirculation in the laser cavity and preventing the light from the multiple wavelength division multiplexed optical signals and a plurality of idler waves generated by four wave mixing between the multiple wavelength division multiplexed optical signals and recovered optical clocks from recirculating in the laser cavity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method for recovery of a clock from each of a plurality of optically encoded wavelength multiplexed signals, the method comprising the steps of:
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providing a phase-insensitive parametric actively mode-locked fiber ring laser including a cavity;
optical modulating a gain in the optical path of the optical cavity of the mode-locked laser;
applying a plurality of wavelength division multiplexed optically encoded input signals to the cavity; and
outputting a plurality of optical pulse streams from the cavity, wherein the gain is modulated in response to the plurality of wavelength division multiplexed optically encoded signals by modulating the spatial pattern of light in the laser cavity thereby locking the spatial pattern of the output pulse stream to a timing wave of one of the optically encoded signals.
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20. A system for recovery of a clock from each of a plurality of optically encoded wavelength multiplexed signals, the system comprising:
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a phase-insensitive parametric actively mode-locked laser including a cavity;
an optically controlled optical modulator in the optical path of the optical cavity of the mode-locked laser;
means for applying an optically encoded input signal to the optically controlled optical modulator; and
means for outputting an optical pulse stream from the system;
wherein the optically controlled optical modulator in response to the optically encoded signal modulates the spatial pattern of light in the laser cavity thereby locking the spatial pattern of the output pulse stream to a timing wave of one of the optically encoded signals.
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Specification