Optical Power Adjustment for SRS Mitigation in Transmission Systems
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Solution Overview
Problem
Current optical transmission systems cannot effectively reduce or eliminate the impact of stimulated Raman scattering (SRS) effects, which cause power fluctuations in communication optical waves across different wavelength bands, leading to instability and reduced transmission capacity.
Innovation Solution
A sending device and receiving device are equipped with a multiplexing unit and optical power adjustment unit that utilize out-of-band detection optical waves to generate power control instructions, allowing for dynamic optical power amplification or attenuation of communication optical waves to mitigate SRS effects, thereby stabilizing the transmission system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple communication optical waves of different wavelengths are simultaneously transmitted in one fiber to increase transmission capacity, then the bandwidth and transmission capacity are improved, but stimulated Raman scattering effects occur causing power fluctuations and instability
Solution Approach 1:
The patent implements a feedback control mechanism where detection optical waves monitor the actual optical power levels in the transmission fiber, and control signals are sent back to adjust the pump power of EDFAs dynamically. This closed-loop feedback system compensates for SRS-induced power fluctuations in real-time, maintaining power stability while enabling multi-wavelength transmission.
Solution Approach 2:
The patent introduces detection optical waves as intermediary signals that travel through the transmission fiber alongside communication waves. These detection waves serve as mediators to indirectly measure the optical power conditions caused by SRS effects, enabling control without directly interfering with the communication signals.
2Measurement precision
If out-of-band detection optical waves are used to monitor power changes, then the accuracy of power measurement is improved, but the device complexity increases due to additional components
Solution Approach 1:
The patent makes the optical fiber serve multiple functions: it acts as both the transmission medium for communication optical waves and the sensing medium for detection optical waves. This multi-functionality allows power measurement without requiring separate dedicated sensing fibers, reducing overall system complexity while maintaining measurement accuracy.
Solution Approach 2:
The detection optical waves utilize the transmission fiber's inherent properties to self-measure the optical power conditions. The fiber itself provides the sensing capability through its interaction with the detection waves, eliminating the need for external complex sensing apparatus and enabling self-diagnosis of power fluctuations.
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 dynamically adjusts optical power to reduce SRS-induced fluctuations, increasing transmission distance and improving the stability and efficiency of the optical transmission system by accurately managing power changes across different wavelength bands.
Implementation Method 1
The non-linear effect includes a stimulated Raman scattering (Stimulated Raman Scattering, SRS) effect. When laser light is used as an incidence source, a Raman scattering process of the medium has a stimulated emission characteristic, and therefore is referred to as an SRS effect.
Implementation Method 2
An optical power of a communication optical wave corresponding to the C band is correspondingly amplified by using the C_EDFA 11, and/or an optical power of a communication optical wave corresponding to the C band is correspondingly attenuated by using the first VOA 13.
Data Source
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AI summary
This application provides a sending device, a receiving device, an optical transmission system, and an optical power control method, and relates to the field of optical communications technologies. The sending device includes: a multiplexing unit and an optical power adjustment unit; the multiplexing unit is configured to send at least two communication optical waves to a fiber channel, and is further configured to send or receive at least two detection optical waves through the fiber channel; and the optical power adjustment unit is configured to: obtain a power control instruction, where the power control instruction is generated according to power change information between the at least two detection optical waves, and perform optical power amplification and/or attenuation on at least one communication optical wave in the at least two communication optical waves according to the power control instruction. In this application, impact caused by an SRS effect on an optical power of the communication optical wave can be rapidly detected by using the power change information between the at least two detection optical waves, so that the optical power adjustment unit dynamically adjusts the optical power of the communication optical wave according to the power control instruction to reduce or eliminate the impact caused by the SRS effect on the optical power.