SiN Optical Demultiplexing Chip With Low-Loss Temperature Stability

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Solution Overview

Problem

Current wavelength division demultiplexing receiver optical chips made of silicon material suffer from high insertion loss, temperature sensitivity, and high costs, requiring temperature cooling control.

Innovation Solution

Implement on-chip integration of a wavelength division demultiplexing receiver optical chip using silicon nitride (SiN) material for passive devices and an active photodetector on a silicon-on-insulator (SOI) platform, compatible with CMOS, to achieve low-loss and temperature-insensitive operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a wavelength demultiplexer is made of silicon material, then the device can be integrated on a silicon platform, but it suffers from high insertion loss and large temperature drift coefficient

Engineering Contradiction:
Improveintegration on silicon platformVSAvoidinsertion loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent employs silicon nitride (SiN) material for the wavelength demultiplexer instead of traditional silicon material. SiN provides lower insertion loss and reduced temperature drift coefficient while maintaining compatibility with silicon-based photodetectors through hybrid integration, thus resolving the contradiction between ease of manufacture and energy loss.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameter from silicon to silicon nitride, which fundamentally alters the optical properties including insertion loss and temperature sensitivity. This material substitution resolves the technical contradiction by providing superior optical performance while maintaining manufacturability through established SiN fabrication processes.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If a wavelength demultiplexer is made of silicon material, then the device can be integrated on a silicon platform, but it requires temperature cooling control

Engineering Contradiction:
Improveintegration on silicon platformVSAvoidtemperature drift coefficient
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent employs silicon nitride (SiN) material for the wavelength demultiplexer instead of traditional silicon material. SiN provides lower insertion loss and reduced temperature drift coefficient while maintaining compatibility with silicon-based photodetectors through hybrid integration, thus resolving the contradiction between ease of manufacture and energy loss.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameter from silicon to silicon nitride, which fundamentally alters the optical properties including insertion loss and temperature sensitivity. This material substitution resolves the technical contradiction by providing superior optical performance while maintaining manufacturability through established SiN fabrication processes.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If silicon material is used for the wavelength demultiplexer, then the device structure can be simplified, but the cost increases due to cooling requirements

Engineering Contradiction:
Improvedevice structureVSAvoidmanufacturing cost
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The patent employs silicon nitride (SiN) material for the wavelength demultiplexer instead of traditional silicon material. SiN provides lower insertion loss and reduced temperature drift coefficient while maintaining compatibility with silicon-based photodetectors through hybrid integration, thus resolving the contradiction between ease of manufacture and energy loss.

Inventive Principle:
Principle #40Composite materials

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 SiN-SOI hybrid integration results in a demultiplexing chip that does not require cooling, with reduced insertion loss and costs, and maintains performance stability, enhancing performance and effectiveness.

Implementation Method 1

a polarization splitter and rotator PSR, configured to perform first processing on the first optical signal to generate a second optical signal, where the second optical signal is in a transverse electric TE mode

Methodology Applied
Scientific EffectPolarization splitting and rotation: Polarisation

Implementation Method 2

at least one wavelength demultiplexer DeMux, configured to perform second processing on the second optical signal to generate a third optical signal, where the third optical signal is a multi-channel single-wavelength optical signal

Methodology Applied
Scientific EffectWavelength division demultiplexing: Diffraction Grating

Implementation Method 3

a photodetector array, configured to convert the third optical signal into an electrical signal

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP4718133A1Optical chip, optical chip manufacturing method, optical signal transmission method, and optical module
Publication Date: 2026.04.01 HUAWEI TECH CO LTD
  • EP4718133A1 patent drawingFigure 1~2
  • EP4718133A1 patent drawingFigure 3~4(b)
  • EP4718133A1 patent drawingFigure 5

AI summary

This application provides an optical chip, an optical chip fabrication method, an optical signal transmission method, and an optical module. The optical chip includes: an optical port, coupled to a fiber and configured to receive a first optical signal from the fiber, where the first optical signal includes a component in a transverse magnetic TM mode; a polarization splitter and rotator PSR, configured to perform first processing on the first optical signal to generate a second optical signal, where the second optical signal is in a transverse electric TE mode, and the second optical signal is a single-channel multi-wavelength optical signal; at least one wavelength demultiplexer DeMux, configured to perform second processing on the second optical signal to generate a third optical signal, where the third optical signal is a multi-channel single-wavelength optical signal; and a photodetector array, configured to convert the third optical signal into an electrical signal. The optical port, the PSR, and the at least one DeMux are made of silicon nitride SiN.