PLC Optical Module Stray Light Blocking via Segmented Groove
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Solution Overview
Problem
The coupling efficiency between a laser and waveguide in PLC optical modules is limited, leading to stray light that causes crosstalk and deteriorates the performance of the optical module.
Innovation Solution
Incorporating a first dividing groove with a WDM and light blocking material inside and a light blocking material on the upper cover plate facing the laser diode, which divides the chip into two parts and blocks stray light from entering the photodiode, reducing crosstalk by obstructing stray light transmission through the upper cladding, sandwich layer, and base of the chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PLC technology is used to replace conventional free-space optical modules, then optical module cost is reduced, but coupling efficiency between laser and waveguide is limited causing stray light and crosstalk
Solution Approach 1:
The chip is divided into two parts by a dividing groove that cuts through the upper cladding, sandwich layer, lower cladding, and base. This segmentation physically separates the laser region from the photodetector region, preventing stray light from causing crosstalk while maintaining the cost-effective PLC structure
Solution Approach 2:
The harmful stray light is extracted and removed from the optical path by filling the dividing groove with light blocking material. This eliminates the crosstalk problem without requiring expensive alternative coupling methods
2Reliability
If light blocking material is added to reduce crosstalk, then receiver performance is improved, but device structure becomes more complex
Solution Approach 1:
The dividing groove that provides structural segmentation is combined with the light blocking function by filling it with light blocking material. This merged structure achieves both mechanical separation and optical isolation without adding separate components, thus improving receiver performance while minimizing structural 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
Significantly reduces crosstalk in the optical module while maintaining a simple structure for low-cost manufacturing, enhancing the performance and reliability of the PLC optical module.
Implementation Method 1
the WDM component may reflect light of a certain band, and transmit light of another band
Implementation Method 2
a light blocking material is arranged on a side of the first upper cover plate facing the first LD
Data Source
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AI summary
The present invention relates to the field of communications technologies and provides an optical module and an optical network system. A first chip is arranged on a lower cover plate, an upper cladding, which is close to a first PD, of the first chip is covered by a first upper cover plate; a first dividing groove divides the first chip into two parts, and a WDM and a light blocking material are arranged inside the first dividing groove, so as to block stray light transmitted inside the upper cladding, a sandwich layer, a lower cladding, and a base of the first chip; and a light blocking material is arranged on a side of the first upper cover plate facing the first LD, so as to block stray light transmitted on a surface of the first chip, thereby blocking the stray light that enters the first PD, and significantly reducing crosstalk of the optical module. Further, the PLC optical module has a simple structure, and therefore is easy to manufacture at a low cost.