Digital Dispersion Compensation Module for Fast Optical Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical signal transmission systems face challenges in rapidly recovering from fiber cuts due to the slow thermal tuning of tunable dispersion compensation modules, which cannot meet the required recovery time of less than 50 ms, especially in high-data-rate systems like DQPSK with narrow dispersion windows.
Innovation Solution
A digital dispersion compensation module (DDCM) is introduced, featuring a multi-port optical circulator and dispersion compensation units with fiber-bragg gratings and optical switches that can selectively provide positive or negative dispersion, allowing for rapid adjustment of dispersion values across a wide wavelength range, enabling fast system recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermally-tuned TDCM is used for dispersion compensation, then dispersion compensation is achieved, but system recovery time exceeds 50 ms requirement
Solution Approach 1:
The patent replaces the thermal tuning mechanism with a mechanical optical switching system. Instead of using thermal effects to gradually change the dispersion properties of TDCM, the invention uses optical switches to rapidly connect different dispersion compensation units, achieving fast dispersion adjustment without thermal delays. This substitution of thermal field with optical/mechanical field resolves the speed limitation.
Solution Approach 2:
The patent introduces dynamic optical switching capability to the dispersion compensation system. The optical switches enable real-time, rapid reconfiguration of the dispersion compensation path in response to system events like fiber cuts. This dynamic switching mechanism allows the system to adapt quickly changing conditions, achieving the required <50 ms recovery time compared to static thermal tuning.
2Adaptability or versatility
If Etalon-based TDCM is used to expand dispersion window, then dispersion tolerance is improved, but recovery process becomes slow due to thermal tuning
Solution Approach 1:
The patent divides the dispersion compensation function into multiple discrete dispersion compensation units, each providing a specific dispersion value. Instead of using a single continuously-tunable TDCM element that requires slow thermal adjustment, the invention segments the compensation into multiple fixed units that can be rapidly selected via optical switching. This segmentation maintains the expanded dispersion window capability while enabling fast recovery through discrete switching.
Solution Approach 2:
The patent pre-configures multiple dispersion compensation units with predetermined dispersion values to handle different fiber path conditions. These units are prepared in advance and can be immediately activated when needed, eliminating the need for gradual thermal tuning during recovery. The preliminary preparation of multiple ready-to-use compensation states enables instant adaptation to different dispersion conditions.
3Device complexity
If fiber-bragg gratings are used for dispersion compensation, then compact structure is achieved, but fast tuning capability is lost
Solution Approach 1:
The patent makes the FBG-based dispersion compensation units universally applicable to multiple dispersion compensation scenarios by designing them as standardized, interchangeable modules. Each FBG unit provides a specific dispersion value and can be rapidly switched into the optical path when needed. This universal modular design maintains the compact FBG structure while enabling fast tuning through optical switching, as the same compact units serve multiple compensation requirements.
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 DDCM achieves rapid dispersion compensation, reducing system recovery time to less than 10 ms, thereby meeting dynamic line protection requirements and maintaining system performance in high-data-rate applications.
Implementation Method 1
at least one of the plurality of dispersion compensation units includes a fiber-Bragg grating (FBG) having a first port and a second port
Data Source
AI summary
Embodiments of present invention provide a digital dispersion compensation module. The digital dispersion compensation module includes a multi-port optical circulator; and a plurality of dispersion compensation units connected to the multi-port optical circulator, wherein at least one of the plurality of dispersion compensation units includes a fiber-bragg grating (FBG) having a first port and a second port; and an optical switch being capable of selectively connecting to one of the first port and the second port of the FBG, wherein the at least one of the plurality of dispersion compensation units is adapted to provide a positive dispersion to an optical signal, from the multi-port optical circulator, when the optical switch connects to the first port of the FBG and is adapted to provide a negative dispersion to the optical signal when the optical switch connects to the second port of the FBG.