Multi-Channel Optical Module Crosstalk Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional multi-channel optical modules face challenges in accurately monitoring optical output power for wavelength multiplexed light due to crosstalk generated by stray light components, which affects the consistency of optical intensity across channels.
Innovation Solution
A multi-channel optical module design incorporating a beam splitter and shielding plates between collimator lenses to prevent stray light from interfering with adjacent channels, ensuring accurate monitoring of optical power and reducing crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a beam splitter is used to monitor optical power, then monitoring accuracy is improved, but light loss occurs due to passing loss
Solution Approach 1:
A beam splitter is introduced as an intermediary component to separate a portion of the optical signal for monitoring purposes. The beam splitter divides the light path, allowing monitor PDs to detect optical power without completely blocking the main signal path, thus enabling monitoring while minimizing light loss compared to direct monitoring approaches.
2Measurement precision
If monitor PDs are placed on the output side of light source chips, then output monitoring is improved, but crosstalk is generated due to stray light from adjacent channels
Solution Approach 1:
The harmful stray light components are extracted and separated from the main optical path using the beam splitter configuration. By placing monitor PDs on the beam-split output side rather than directly on the light source chip output, the design extracts only the necessary monitoring signal while leaving the main signal path intact, thereby reducing crosstalk from adjacent channels.
Solution Approach 2:
The beam splitter acts as an intermediary that separates the monitoring function from the main signal path. This intermediary component allows monitor PDs to receive a portion of the optical signal for monitoring purposes while preventing direct exposure to stray light from adjacent channels that would cause crosstalk.
3Productivity
If collimator lenses are used to focus light, then coupling efficiency is improved, but stray light components exceed the effective diameter and cause crosstalk
Solution Approach 1:
The beam splitter is positioned as an intermediary component between the collimator lenses and the optical multiplexer. This intermediary structure allows the collimator lenses to focus light efficiently for coupling while the beam splitter intercepts and directs stray light components away from adjacent channels, preventing crosstalk.
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 effectively suppresses crosstalk between adjacent channels, maintaining consistent optical output power across multiple wavelength channels, as demonstrated by minimal changes in current values when operating single versus multiple channels.
Implementation Method 1
a beam splitter 51 and multiplexed
Implementation Method 2
collimator lenses 31a to 31d and multiplexed
Implementation Method 3
an optical multiplexer 20 through collimator lenses 31a to 31d and multiplexed
Implementation Method 4
The output of the optical multiplexer 20 is multiplexed with all wavelength channels as wavelength multiplexed light through a condenser lens 32 and is coupled to an optical fiber 41
Implementation Method 5
monitors PD 153a to 153d for monitoring optical power branched from the beam splitter
Data Source
AI summary
Crosstalk between adjacent channels is suppressed when monitoring output power. A multi-channel optical module for multiplexing and outputting a plurality of wavelength channels, which includes a plurality of light sources each having a different wavelength, a plurality of collimator lenses coupled to an output of each of the plurality of light sources, a beam splitter coupled to an output of each of the plurality of collimator lenses, a plurality of monitor PDs for monitoring optical power branched from the beam splitter, and a shielding plate installed between the plurality of collimator lenses.