JP2003258348A5

JP2003258348A5 -

Info

Publication number: JP2003258348A5
Application number: JP2002057600A
Authority: JP
Filing date: 2002-03-04
Publication date: 2005-07-21
Anticipated expiration: 2022-03-04

Claims

An optical amplifier that optically amplifies signal light input to an input end and outputs the optically amplified signal light from an output end,
An optical waveguide that is provided on a signal light propagation path from the input end to the output end, and that a Tm element is added to the optical waveguide region to optically amplify the signal light;
Excitation light supply means for supplying excitation light to the optical waveguide;
A transmission characteristic variable optical component which is provided in series with the optical waveguide on the signal light propagation path, and whose transmission characteristic at the signal light wavelength is variable;
A power or wave number of signal light input to the input terminal, or a signal light detection unit that detects the power of light output from the output terminal;
Based on the detection result by the signal light detector, the power of the excitation light supplied from the excitation light supply means to the optical waveguide is adjusted, and the transmission characteristic of the transmission characteristic variable optical component at the signal light wavelength is also adjusted. And a control unit that controls both the magnitude of the gain of signal light amplification and the shape of the gain spectrum in the optical waveguide.

The pumping light supply means supplies pumping light having a wavelength of 1.05 μm band or wavelength of 1.4 μm to the optical waveguide, and pumping light having a wavelength of 1.2 μm or wavelength of 1.55 to 1.65 μm The optical amplifier according to claim 1, wherein the optical amplifier is supplied to an optical waveguide.

The signal light detection unit has a power of signal light output from the output end at a wavelength of two or more within a gain band of signal light amplification in the optical waveguide, gain of signal light amplification in the optical waveguide, or ASE light. The optical amplifier according to claim 1, wherein the power of the optical amplifier is detected.

The signal light detection unit detects the gain of signal light amplification in the optical waveguide by detecting the power of spontaneous emission light emitted to the side of the optical waveguide. Optical amplifier.

The signal light detector is
The total power of the input signal light or the total power of the output light, and
The power of the signal light output from the output end at one or more wavelengths within the gain band of the signal light amplification in the optical waveguide, the gain of the signal light amplification in the optical waveguide, or the power of the ASE light;
The optical amplifier according to claim 1, wherein the optical amplifier is detected.

6. The optical amplifier according to claim 5, wherein one or more wavelengths within a gain band of signal light amplification in the optical waveguide are on an end wavelength side or a long wavelength side in the wavelength band of signal light.

The signal light detector is
An optical branching coupler for branching out a part of the power of the light output from the optical waveguide;
A filter that selectively transmits light of a specific wavelength among the light extracted by the optical branching coupler;
The optical amplifier according to claim 3 or 5, characterized in that it has a light receiving portion for detecting light power of said specific wavelength transmitted through the filter.

The signal light detector is
An optical branching coupler for branching out a part of the power of the light output from the optical waveguide;
A diffraction grating for diffracting the light extracted by the optical branching coupler;
The optical amplifier according to claim 3, further comprising: a light receiving unit that detects power of light having a specific wavelength out of light diffracted by the diffraction grating.

9. The optical amplifier according to claim 8, wherein the signal light detection unit detects the wave number of the signal light input to the input terminal based on a spectrum of light diffracted by the diffraction grating.

2. The optical amplifier according to claim 1, wherein the signal light detection unit detects the total power of the signal light input to the input terminal and the total power of the light output from the output terminal.

2. The optical amplifier according to claim 1, wherein the signal light detection unit detects the wave number of the signal light input to the input terminal based on information delivered from other than the signal light main line.

2. The optical amplifier according to claim 1, wherein the transmission characteristic variable optical component has variable transmittance at a signal light wavelength.

The controller is
Based on the wave number of the signal light input to the input end, the power of the pumping light having a wavelength of 1.2 μm or 1.55 to 1.65 μm supplied from the pumping light supply unit to the optical waveguide is adjusted. And adjusting the transmittance of the transmission characteristic variable optical component at the signal light wavelength based on the target value of the signal light power input to the input terminal or the signal light power to be output from the output terminal, Control the shape of the gain spectrum of signal light amplification in the waveguide,
The power of the pumping light supplied from the pumping light supplying means to the optical waveguide is adjusted to control the power of the signal light of each wavelength output from the output terminal. The optical amplifier according to claim 12.

Power fluctuation amount ΔP _in [dB] of signal light of each wavelength input to the input end, target power fluctuation amount ΔP _out [dB] of signal light of each wavelength to be output from the output end, and For the coefficient X having a value corresponding to the wave number of the signal light input to the input terminal, the transmittance variation ΔA [dB] of the transmission characteristic variable optical component is “ΔA = X · (ΔP _in −ΔP _out )”. 14. The optical amplifier according to claim 13, represented by the formula:

The optical amplifier according to claim 1, wherein the transmission characteristic variable optical component has a variable slope of a loss spectrum in a signal light wavelength region.

The controller is
Based on the wave number of the signal light input to the input end, the power of the pumping light having a wavelength of 1.2 μm or 1.55 to 1.65 μm supplied from the pumping light supply unit to the optical waveguide is adjusted. And adjusting the slope of the loss spectrum of the transmission characteristic variable optical component in the signal light wavelength range based on the target value of the signal light power input to the input terminal or the signal light power to be output from the output terminal. , Control the shape of the gain spectrum of the signal light amplification in the optical waveguide,
The power of the pumping light supplied from the pumping light supplying means to the optical waveguide is adjusted to control the power of the signal light of each wavelength output from the output terminal. The optical amplifier according to claim 15.

Power fluctuation amount ΔP _in [dB] of signal light of each wavelength input to the input end, target power fluctuation amount ΔP _out [dB] of signal light of each wavelength to be output from the output end, and For the coefficient Y having a value corresponding to the wave number of the signal light input to the input terminal, the variation ΔS [dB] of the loss spectrum slope of the transmission characteristic variable optical component in the signal light wavelength region is “ΔS = Y · The optical amplifier according to claim 16, wherein the optical amplifier is expressed by an expression (ΔP _in −ΔP _out ) ”.

16. The optical amplifier according to claim 15, wherein the transmission characteristic variable optical component is capable of shifting the shape of the loss spectrum in the signal light wavelength region in the wavelength axis direction.

The controller is
Based on the wave number of the signal light input to the input terminal, the inclination of the loss spectrum and the shift amount in the wavelength axis direction of the transmission characteristic variable optical component in the signal light wavelength range are adjusted, and the signal of each wavelength input to the input terminal Based on the light power and the target power of the signal light of each wavelength to be output from the output end, the slope of the loss spectrum of the transmission characteristic variable optical component in the signal light wavelength region is adjusted, and the signal in the optical waveguide Control the shape of the gain spectrum of optical amplification,
The power of the pumping light supplied from the pumping light supplying means to the optical waveguide is adjusted to control the power of the signal light of each wavelength output from the output terminal. The optical amplifier according to claim 18.

An optical amplifier that optically amplifies signal light input to an input end and outputs the optically amplified signal light from an output end,
An optical waveguide that is provided on a signal light propagation path from the input end to the output end, and that a Tm element is added to the optical waveguide region to optically amplify the signal light;
Excitation light supply means for supplying excitation light having a wavelength of 1.2 μm band or a wavelength of 1.55 to 1.65 μm band to the optical waveguide;
A temperature detector for detecting the temperature of the optical waveguide or the vicinity thereof;
Based on the temperature detection result by the temperature detector, the power of the pumping light supplied from the pumping light supply means to the optical waveguide is adjusted, and the gain magnitude and gain spectrum of the signal light amplification in the optical waveguide are adjusted. An optical amplifier comprising: a control unit that controls both of the shapes.

An optical amplifier that optically amplifies signal light input to an input end and outputs the optically amplified signal light from an output end,
An optical waveguide that is provided on a signal light propagation path from the input end to the output end, and that a Tm element is added to the optical waveguide region to optically amplify the signal light;
Excitation light supply means for supplying excitation light to the optical waveguide;
A transmission characteristic variable optical component provided on the signal light propagation path, the transmission characteristic of the signal light wavelength being variable;
A temperature detector for detecting the temperature of the optical waveguide or the vicinity thereof;
Based on the temperature detection result by the temperature detection unit, the transmission characteristic of the transmission characteristic variable optical component at the signal light wavelength is adjusted, and both the magnitude of the gain of the signal light amplification and the shape of the gain spectrum in the optical waveguide are adjusted. An optical amplifier comprising: a control unit that controls the optical amplifier.

The optical amplifier according to claim 21, wherein the transmission characteristic variable optical component has a variable slope of a loss spectrum in a signal light wavelength region.

23. The optical amplifier according to claim 15, wherein the transmission characteristic variable optical component comprises a plurality of Mach-Zehnder interferometers.

23. The optical amplifier according to claim 22, wherein the transmission characteristic variable optical component is capable of shifting the shape of a loss spectrum in a wavelength direction.

25. The optical amplifier according to claim 24, wherein the transmission characteristic variable optical component is capable of controlling the slope of the loss spectrum and the shift in the wavelength direction independently of each other.

25. The optical amplifier according to claim 24, wherein the transmission characteristic variable optical component has a shiftable amount in the wavelength direction of the loss spectrum of 10 nm or more.

25. The optical amplifier according to claim 24, wherein the transmission characteristic variable optical component has a shiftable amount in the wavelength direction of a loss spectrum of 15 nm or more.

An optical communication system comprising the optical amplifier according to any one of claims 1, 20, and 21, wherein signal light is transmitted and the signal light is optically amplified by the optical amplifier.