Optical Cross-Connect Device Using THz Signal Processing

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Solution Overview

Problem

Current optical cross-connect apparatuses face limitations in switching speed, cost, integration degree, and expansion scale, with 3D-MEMS systems having low switching speed and silicon-based systems experiencing high insertion loss and polarization-dependent issues.

Innovation Solution

The proposed optical signal processing method and apparatus utilize terahertz (THz) signal processing with phase modulation and frequency mixing, integrated using CMOS technology, to enhance switching speed and reduce costs, while increasing integration and expansion capabilities through directional beamforming and phase adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If all-to-optical switching elements are used to improve switching speed, then switching speed is improved, but device complexity and cost increase due to requiring multiple optical switches per fiber

Engineering Contradiction:
Improveswitching speedVSAvoiddevice complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The optical switch is divided into multiple switching elements arranged in a matrix, where each switching element corresponds to a specific input-output fiber pair. This segmentation allows the system to achieve all-to-optical switching capability while managing complexity through modular organization of switching elements rather than requiring a monolithic complex switch.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Optical add-drop multiplexers (OADM s) are introduced as intermediary devices between the optical switch and the optical fibers. These OADM s enable wavelength-selective signal routing and facilitate the connection between multiple optical switches and fibers without requiring each fiber to be directly connected to every switching element, thereby reducing the overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple optical switches are connected to each fiber to improve switching capability, then switching capability is improved, but the number of optical switches increases leading to higher cost

Engineering Contradiction:
Improveswitching capabilityVSAvoidnumber of optical switches
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The optical add-drop multiplexer is designed to perform multiple functions: it acts as a wavelength selector, a signal router, and a interface between different optical switches. This multi-functionality allows a single OADM to replace what would otherwise require multiple dedicated components, reducing the total number of optical switches needed in the system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces the wavelength dimension as an additional degree of freedom for signal routing. By utilizing wavelength-selective switching in conjunction with spatial switching, the system achieves enhanced switching capability without proportionally increasing the number of optical switches, effectively adding a new dimension to the switching architecture.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If conventional electrical switching is used to reduce device complexity, then device complexity is reduced, but switching speed decreases due to electro-optical conversion requirements

Engineering Contradiction:
Improvedevice complexityVSAvoidswitching speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The patent replaces electrical switching mechanisms with all-optical switching elements. The switching elements directly manipulate optical signals without converting them to electrical signals, eliminating the electro-optical conversion process. This substitution maintains relatively simple device structure while achieving significantly faster switching speeds compared to conventional electrical switching systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach significantly increases the switching speed of optical cross-connect apparatuses, reduces costs, and enhances integration and expansion scales by leveraging THz-related components and CMOS integration, addressing the limitations of existing technologies.

Implementation Method 1

each of the optical switching elements having an input optically connected to a corresponding one of the input fibers and an output optically connected to a corresponding one of the output fibers, each of the optical switching elements being modulated by a corresponding one of the modulation signals

Methodology Applied
Scientific EffectOptical modulation: Phase Modulation

Data Source

PatentEP3370430B1Optical signal processing method and optical cross-connect device
Publication Date: 2020.06.03 HUAWEI TECH CO LTD
  • EP3370430B1 patent drawingFigure 1
  • EP3370430B1 patent drawingFigure 2
  • EP3370430B1 patent drawingFigure 3

AI summary

Embodiments of the present invention disclose an optical signal processing method and an optical cross-connect apparatus. The method includes: first receiving, by an input port i of the optical cross-connect apparatus, a first optical signal; performing, based on the first optical signal by a transmit-end signal processing module i, first phase modulation processing and first frequency mixing processing to obtain a THz signal that carries signal information of the first optical signal; transmitting, by a transmit-end antenna i, the THz signal; receiving, by a receive-end antenna j, the THz signal; performing, based on the THz signal by a receive-end signal processing module j, second phase modulation processing and second frequency mixing processing to obtain a second optical signal that carries the signal information; and outputting, by an output port j, the second optical signal. Implementing the embodiments of the present invention helps increase a switching speed of the optical cross-connect apparatus, reduce apparatus costs, and increase an integration degree and an expansion scale of the apparatus.