Dummy Light Spectral Shaping for WDM Idle-Band Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical communication systems using wavelength division multiplexing (WDM), distinguishing between dummy light and service light is challenging due to the stimulated Raman scattering (SRS) effect, which affects power distribution and increases jitter when the optical bandwidth is not fully occupied, necessitating the use of dummy light to stabilize the system.
Innovation Solution
A method involving a light emitting apparatus that generates multi-wavelength dummy light, applies spectrum shaping to create distinct spectral features for the dummy light, and multiplexes it with service light to enable effective differentiation through spectral analysis, using techniques like comb filters and band-stop optical filters to create periodic intensity variations and dip features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dummy light is used to occupy idle bands in WDM systems, then system stability is improved, but the ability to distinguish dummy light from service light deteriorates
Solution Approach 1:
The patent applies local quality by giving dummy light a specific spectral characteristic (comb-shaped spectrum with periodic peaks and valleys) that distinguishes it from service light in specific wavelength regions. The spectrum shaping unit creates this localized spectral pattern in the dummy light without affecting the service light, enabling identification while maintaining system stability.
Solution Approach 2:
The patent uses spectral feature modification analogous to color changes, where the dummy light is given a distinctive spectral pattern (comb-shaped spectrum) through spectrum shaping. This spectral 'color' differentiation allows the receiving end to identify dummy light versus service light based on their different spectral characteristics.
2Difficulty of detecting and measuring
If spectrum shaping is applied to dummy light, then spectral distinction from service light is improved, but device complexity increases
Solution Approach 1:
The patent introduces a spectrum shaping unit as an intermediary component between the dummy light source and the multiplexing point. This intermediary device processes the dummy light to create the desired comb-shaped spectrum before it enters the optical fiber, simplifying the overall system architecture by concentrating the spectral modification function in a dedicated component.
Solution Approach 2:
The patent replaces complex modulation mechanisms with a simpler spectrum shaping approach using optical filters or gratings. Instead of modulating the service light or using complex time-division multiplexing, the system uses passive or active optical filtering to create the distinctive spectral pattern, reducing mechanical and electronic complexity.
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 method allows for clear distinction between service and dummy light by exploiting different spectral features, ensuring stable system operation without additional modulation, and enabling efficient utilization of idle bands.
Implementation Method 1
The light emitting apparatus performs spectrum shaping on the first multi-wavelength dummy light to obtain second multi-wavelength dummy light. A spectral feature of the second multi-wavelength dummy light obtained through the spectrum shaping is different from a spectral feature of service light.
Implementation Method 2
When the optical bandwidth occupied by the WDM gradually increases and enters a C+L band, dynamic adding or dropping of a wavelength in a network is affected by a stimulated Raman scattering (Stimulated Raman scattering, SRS) effect
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
Embodiments of this application disclose a dummy light transmission method, a dummy light identification method, and a related device. Specifically, a light emitting apparatus performs spectrum shaping on first multi-wavelength dummy light generated by a dummy light source, to obtain second multi-wavelength dummy light, so that a spectral feature of the second multi-wavelength dummy light is different from a spectral feature of service light. The light emitting apparatus selects target dummy light from the second multi-wavelength dummy light to fill an idle band. A light receiving apparatus receives the service light and the target dummy light from the light emitting apparatus. Because the target dummy light and the service light have different spectral features, the light receiving apparatus can effectively distinguish the service light from the target dummy light through spectrum detection and spectrum analysis. It should be understood that a manner of constructing a spectral feature through spectrum shaping is simple to implement, and no additional modulation needs to be performed on dummy light.