OPTICAL ADD/DROP MULTIPLEXER AND METHOD FOR ADDING/DROPPING OPTICAL SIGNAL
First Claim
1. An optical add/drop multiplexer that processes wavelength multiplexed light containing reference light and a wavelength-division multiplexed optical signal in which a plurality of optical signals are multiplexed, the optical add/drop multiplexer comprising:
- an optical splitter that splits the wavelength multiplexed light to generate first wavelength multiplexed light and second wavelength multiplexed light;
a receiver that generates an electric signal representing the second wavelength multiplexed light;
a frequency estimator that estimates a difference in optical frequency between the reference light and an optical signal specified from among the plurality of optical signals multiplexed in the wavelength-division multiplexed optical signal, based on the electric signal generated by the receiver;
a light source that generates first light and second light, an optical frequency of the second light being shifted by the estimated difference with respect to an optical frequency of the first light;
a demodulator that generates a dropped signal representing the specified optical signal based on the electric signal;
a drive signal generator that generates a drive signal in accordance with an inverted signal of the dropped signal;
an optical modulator that modulates the second light in accordance with the drive signal to generate a modulated optical signal; and
a non-linear optical medium to which the first wavelength multiplexed light, the first light and the modulated optical signal are input.
1 Assignment
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Accused Products
Abstract
OADM processes input light containing reference light and multiplexed optical signals. A splitter splits the input light to generate first and second input light. A receiver generates an electric signal representing the second input light. An estimator estimates a difference in optical frequency between the reference light and a specified optical signal based on the electric signal. Alight source generates first and second light. An optical frequency of the second light is shifted by the estimated difference with respect to that of the first light. A demodulator generates a dropped signal representing the specified optical signal. A drive signal generator generates a drive signal in accordance with an inverted signal of the dropped signal. A modulator modulates the second light with the drive signal to generate a modulated optical signal. The first input light, the first light and the modulated optical signal are input to non-linear optical medium.
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Citations
13 Claims
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1. An optical add/drop multiplexer that processes wavelength multiplexed light containing reference light and a wavelength-division multiplexed optical signal in which a plurality of optical signals are multiplexed, the optical add/drop multiplexer comprising:
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an optical splitter that splits the wavelength multiplexed light to generate first wavelength multiplexed light and second wavelength multiplexed light; a receiver that generates an electric signal representing the second wavelength multiplexed light; a frequency estimator that estimates a difference in optical frequency between the reference light and an optical signal specified from among the plurality of optical signals multiplexed in the wavelength-division multiplexed optical signal, based on the electric signal generated by the receiver; a light source that generates first light and second light, an optical frequency of the second light being shifted by the estimated difference with respect to an optical frequency of the first light; a demodulator that generates a dropped signal representing the specified optical signal based on the electric signal; a drive signal generator that generates a drive signal in accordance with an inverted signal of the dropped signal; an optical modulator that modulates the second light in accordance with the drive signal to generate a modulated optical signal; and a non-linear optical medium to which the first wavelength multiplexed light, the first light and the modulated optical signal are input. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An optical add/drop multiplexer that processes wavelength multiplexed light containing reference light and a wavelength-division multiplexed optical signal in which a plurality of optical signals are multiplexed, the optical add/drop multiplexer comprising:
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an optical splitter that splits the wavelength multiplexed light to generate first wavelength multiplexed light and second wavelength multiplexed light; a receiver that generates an electric signal representing the second wavelength multiplexed light; a frequency estimator that estimates a difference in optical frequency between the reference light and an optical signal specified from among the plurality of optical signals multiplexed in the wavelength-division multiplexed optical signal, based on the electric signal generated by the receiver; a light source that generates first light, second light, and third light, an optical frequency of the second light being shifted by the estimated difference with respect to an optical frequency of the first light, and an optical frequency of the third light being shifted by a specified amount with respect to the optical frequency of the first light; a demodulator that generates a dropped signal representing the specified optical signal based on the electric signal; a drive signal generator that generates a first drive signal in accordance with an inverted signal of the dropped signal and a second drive signal in accordance with an added signal; an optical modulator that modulates the second light in accordance with the first drive signal to generate a first modulated optical signal and modulates the third light in accordance with the second drive signal generate a second modulated optical signal; and a non-linear optical medium to which the first wavelength multiplexed light, the first light, the first modulated optical signal and the second modulated optical signal are input.
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10. An optical add/drop multiplexer that processes wavelength multiplexed light containing reference light and a wavelength-division multiplexed optical signal in which a plurality of optical signals are multiplexed, the optical add/drop multiplexer comprising:
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an optical splitter that splits the wavelength multiplexed light to generate first wavelength multiplexed light and second wavelength multiplexed light; a receiver that generates an electric signal representing the second wavelength multiplexed light; a frequency estimator that estimates a difference frequency between an optical frequency of the reference light and an optical frequency of an optical signal specified from among the plurality of optical signals multiplexed in the wavelength-division multiplexed optical signal, based on the electric signal generated by the receiver; a demodulator that generates a dropped signal representing the specified optical signal based on the electric signal; an oscillator that generates an oscillation signal of the estimated difference frequency; a drive signal generator that generates a drive signal in accordance with an inverted signal of the dropped signal and the oscillation signal; and an optical modulator that modulates the first wavelength multiplexed light in accordance with the drive signal to generate an output wavelength-division multiplexed optical signal.
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11. An optical add/drop multiplexer that processes wavelength multiplexed light containing reference light and a wavelength-division multiplexed optical signal in which a plurality of optical signals are multiplexed, the optical add/drop multiplexer comprising:
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an optical splitter that splits the wavelength multiplexed light to generate first wavelength multiplexed light and second wavelength multiplexed light; a receiver that generates an electric signal representing the second wavelength multiplexed light; a frequency estimator that estimates a difference frequency between an optical frequency of the reference light and an optical frequency of an optical signal specified from among the plurality of optical signals multiplexed in the wavelength-division multiplexed optical signal, based on the electric signal generated by the receiver; a demodulator that generates a dropped signal representing the specified optical signal based on the electric signal; an oscillator that generates an oscillation signal of the estimated difference frequency; a drive signal generator that generates a drive signal in accordance with an inverted signal of the dropped signal and the oscillation signal; a light source that generates continuous wave light having an optical frequency different from that of the wavelength-division multiplexed optical signal; an optical modulator that modulates the continuous wave light in accordance with the drive signal to generate a modulated optical signal; and a non-linear optical medium to which the first wavelength multiplexed light and the modulated optical signal are input.
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12. An optical signal add/drop method that processes wavelength multiplexed light containing reference light and a wavelength-division multiplexed optical signal in which a plurality of optical signals are multiplexed, the method comprising:
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splitting the wavelength multiplexed light to generate first wavelength multiplexed light and second wavelength multiplexed light; generating an electric signal representing the second wavelength multiplexed light; estimating a difference in optical frequency between the reference light and an optical signal specified from among the plurality of optical signals multiplexed in the wavelength-division multiplexed optical signal, based on the electric signal; generating first light and second light, an optical frequency of the second light being shifted by the estimated difference with respect to an optical frequency of the first light; generating a dropped signal representing the specified optical signal based on the electric signal; generating a drive signal in accordance with an inverted signal of the dropped signal; modulating the second light in accordance with the drive signal to generate a modulated optical signal; and inputting the first wavelength multiplexed light, the first light and the modulated optical signal to a non-linear optical medium. - View Dependent Claims (13)
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Specification