Semiconductor Device With Diagonal Stray Light Extraction
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Solution Overview
Problem
Existing semiconductor devices with variable wavelength light sources face limitations in photodiode arrangement due to stray light emission, which affects monitoring accuracy and flexibility.
Innovation Solution
The semiconductor device incorporates a substrate with semiconductor lasers, forward and backward optical multiplexers, and backward waveguides, including a main waveguide and lateral waveguides that output stray light diagonally from the side faces, preventing stray light from entering the photodiode and improving monitoring accuracy by allowing greater flexibility in photodiode placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If lateral waveguides are used to emit stray light from the front end face, then stray light can be prevented from entering the photodiode, but the photodiode arrangement is limited and flexibility is reduced
Solution Approach 1:
The lateral waveguides are configured to output stray light diagonally toward the side faces of the substrate rather than from the front end face. This spatial reconfiguration in a different dimension (from front-face emission to side-face diagonal emission) allows the photodiode to be freely positioned on the front end face without receiving stray light, thus resolving the contradiction between monitoring accuracy and arrangement flexibility
Solution Approach 2:
The waveguide structure is divided into main waveguides for signal light and separate lateral waveguides for stray light. This segmentation allows independent control of signal and stray light paths, enabling stray light to be directed away from the photodiode while maintaining signal transmission to the photodiode, thereby achieving both high monitoring accuracy and flexible photodiode placement
2Ease of operation
If photodiode is positioned to receive signal light, then monitoring function is achieved, but stray light may enter the photodiode and reduce monitoring accuracy
Solution Approach 1:
Stray light is extracted from the main optical path and directed through separate lateral waveguides to a different output location (side faces). This extraction removes the harmful stray light from the photodiode's reception path while maintaining the signal light path, allowing the photodiode to be freely positioned for easy operation without compromising monitoring accuracy
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
This configuration effectively reduces stray light interference with monitoring light, enhancing monitoring accuracy and freedom in photodiode arrangement, thereby stabilizing wavelength monitoring and improving the device's operational efficiency.
Implementation Method 1
a forward optical multiplexer provided on the substrate to multiplex forward output light of the plurality of semiconductor lasers and output the multiplexed light to the front end face
Implementation Method 2
backward waveguides provided on the substrate and connected to an output section of the backward optical multiplexer
Data Source
AI summary
According to the present invention, a semiconductor device includes a substrate comprising a front end face, a rear end face and side faces, a plurality of semiconductor lasers provided on the substrate, a forward optical multiplexer to multiplex forward output light of the plurality of semiconductor lasers and output the multiplexed light to the front end face, a backward optical multiplexer to multiplex backward output light of the plurality of semiconductor lasers and output the multiplexed light to the rear end face and a plurality of backward waveguides connected to an output section of the backward optical multiplexer, wherein the plurality of backward waveguides includes a main waveguide disposed at a center of the output section and a plurality of lateral waveguides disposed on both sides of the main waveguide to bend toward the side faces and output light from the side faces diagonally to the side faces.