MEMS Optical Switch Waveguide Segmentation

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Solution Overview

Problem

Current optical switches face challenges in achieving microsecond-level switching speed, low insertion loss, and a large number of ports while maintaining low costs, particularly due to high loss in silicon-based waveguide switches and limitations in MEMS optical switches.

Innovation Solution

The optical switch design features a substrate-based configuration with a first and second immovable waveguide in a plane, and a movable waveguide that optically decouples and couples with them to avoid intersection losses, utilizing an MEMS optical waveguide for high-speed operation and a support component for stability, allowing for microsecond-level switching with low insertion loss and a large number of ports.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a conventional MEMS optical switch is used, then the insertion loss is low and the extinction ratio is high, but the switching speed is limited to millisecond level

Engineering Contradiction:
Improveswitching speedVSAvoidmicro reflector rotation mechanism
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical rotation of micro reflectors in conventional MEMS switches with a waveguide-based optical switching mechanism. The movable waveguide section is actuated by an actuator to change its position relative to fixed waveguides, enabling optical path switching without mechanical rotation. This substitution achieves microsecond-level switching speed while eliminating the mechanical inertia limitations of traditional MEMS reflector systems.

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

2Loss of energy

If a silicon-based waveguide optical switch is used, then the switching speed reaches microsecond level and integration is high, but the insertion loss increases rapidly with the size of the optical switch matrix

Engineering Contradiction:
Improveinsertion lossVSAvoidscalability to large-scale matrix
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent segments the optical switch into multiple independent modules, each comprising fixed waveguides and a movable waveguide section. Each module can be independently controlled by its own actuator, allowing the system to achieve large-scale switching functionality through modular composition. This segmentation reduces the insertion loss per switching element and enables scalable deployment from small to large matrices without proportional loss increase.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a vertical dimension to the waveguide structure by positioning the movable waveguide section above or below the fixed waveguides in a three-dimensional configuration. This vertical arrangement allows optical paths to be switched by moving the movable waveguide section along the vertical axis, reducing planar congestion and enabling larger scale matrices with lower insertion loss compared to traditional two-dimensional waveguide layouts.

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

3Loss of energy

If waveguides are arranged to intersect in the plane, then the routing is simple, but the loss increases due to intersection points

Engineering Contradiction:
Improveintersection lossVSAvoidwaveguide arrangement structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent resolves waveguide intersections by transitioning from a two-dimensional planar arrangement to a three-dimensional configuration. The movable waveguide section is positioned in a different vertical layer or height level than the fixed waveguides, allowing optical paths to cross without physical intersection. This vertical separation eliminates intersection losses while maintaining simple routing topology, as the movable waveguide can still be actuated to couple with any fixed waveguide by changing its vertical position.

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

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 design achieves microsecond-level switching speed, low insertion loss, and a large quantity of ports while reducing fabrication complexity and costs, enhancing the performance and efficiency of optical switching systems.

Implementation Method 1

A conventional MEMS optical switch is usually based on an electrostatic-actuation micro reflector structure

Methodology Applied
Scientific EffectElectrostatic actuation: Electrostatics

Implementation Method 2

the first movable waveguide and the first waveguide form a first coupler, and the first output section of the first movable waveguide and the second waveguide form a second coupler

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3486700B1Optical switch and optical switching system
Publication Date: 2023.01.04 HUAWEI TECH CO LTD
  • EP3486700B1 patent drawingFigure 1~2
  • EP3486700B1 patent drawingFigure 3~4
  • EP3486700B1 patent drawingFigure 5~6

AI summary

This application discloses an optical switch and an optical switching system. The optical switch includes a first waveguide, a second waveguide, and a first movable waveguide, and the first waveguide and the second waveguide are immovable relative to a substrate; the first waveguide and the second waveguide are located in a first plane, and the first waveguide and the second waveguide do not intersect; the first movable waveguide is movable relative to the substrate; when the first movable waveguide is at a first location, the first movable waveguide is optically decoupled from the first waveguide and the second waveguide, and the optical switch is in a through state; and when the first movable waveguide is at a second location, the first movable waveguide is optically coupled to the first waveguide and the second waveguide, and the optical switch is in a drop state. The optical switch in embodiments of this application includes two fixed uncrossed waveguides and one first movable waveguide that is movable, so that a loss caused by intersection is avoided. In addition, when the optical switch is in both the states, an optical signal passes through only an adiabatic coupler or only a curved waveguide, thereby further reducing a loss.