Optical Amplification Control Apparatus for WDM Network Stability
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Solution Overview
Problem
In WDM networks with ring or mesh configurations, power fluctuations due to polarization dependency and loss fluctuations lead to inaccurate Automatic Gain Control (AGC) and potential oscillations, as these fluctuations propagate and affect signals without termination points, causing resonance.
Innovation Solution
An optical amplification control apparatus with branch and filter means to isolate and amplify specific wavelengths, allowing for precise AGC based on additional optical signals that are less affected by transmission path fluctuations, thereby stabilizing amplification across varying input wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AGC control is performed using input and output signals of an optical amplifier, then amplification control is achieved, but power fluctuation propagates and affects signals without termination points, causing resonance and oscillation
Solution Approach 1:
The patent extracts the additional optical signal with a predetermined wavelength from the WDM optical signal using optical filters. This extracted signal is then used for AGC control, separating the control function from the main signal transmission path to prevent fluctuation propagation while maintaining control accuracy.
Solution Approach 2:
The patent introduces an additional optical signal as an intermediary carrier for AGC control. This intermediary signal is added to the WDM signal, extracted at control points, and used to generate control signals for optical amplifiers, thereby mediating the control function without allowing main signal fluctuations to propagate.
2Object-generated harmful factors
If ALC control is used to suppress power fluctuation propagation, then fluctuation control is improved, but when the number of input wavelengths changes rapidly, the output power per wavelength becomes unstable
Solution Approach 1:
The patent implements feedback control by measuring the power of the extracted additional optical signal at multiple points and using this information to generate control signals that adjust optical amplifier gain. This feedback mechanism maintains output power stability even when the number of input wavelengths changes rapidly.
Solution Approach 2:
The additional optical signal serves multiple functions: it acts as a carrier for AGC control, enables fluctuation suppression, and provides a reference for maintaining output power stability across varying wavelength conditions, making the control system universally applicable to different network configurations.
3Measurement precision
If additional optical signal extraction is performed using optical filters, then AGC control accuracy is improved, but device complexity increases due to additional branch and filter means
Solution Approach 1:
The patent segments the WDM optical signal by extracting only the additional optical signal with a predetermined wavelength using optical filters. This segmentation allows precise measurement of the control signal while isolating it from the complex multi-wavelength signal, improving AGC control accuracy without requiring analysis of the entire WDM signal.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables high-accuracy control of optical signal amplification, suppressing fluctuation transfer and preventing oscillations, ensuring consistent output power per wavelength regardless of input wavelength changes.
Implementation Method 1
an optical amplifier 4, a pump light source 7
Data Source
AI summary
An optical amplification control apparatus is provided with: a first branch unit for branching an optical signal to which an additional optical signal with a predetermined wavelength has been added in a self node or a nearest node; a first filter unit for extracting the additional optical signal from one optical signal into which the first branch unit has branched; an amplification unit for amplifying the other optical signal into which the first branch unit has branched; a second branch unit for branching the optical signal amplified by the amplification unit; a second filter unit for extracting the additional optical signal from one optical signal into which the second branch unit has branched; and a first control unit for performing automatic gain control of the amplification unit based on the additional optical signal extracted by the first filter unit, and the additional optical signal extracted by the second filter unit.