Tunable Microring Resonator With MEMS Actuator For Variable FSR

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing optical filters with constant free spectral range (FSR) lack flexibility to adapt to changing network conditions, limiting their ability to handle varying channel spacings in optical networks, particularly in data centers with high traffic where more wavelengths are needed to increase data transmission capacity.

Innovation Solution

A tunable microring resonator using Micro-Electro-Mechanical System (MEMS) technology, which allows for the adjustment of the optical coupling between primary and secondary waveguides of varying lengths to change the cavity length and thus the FSR, enabling broad tunability of the frequency comb and filter responses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a constant mechanical dimension is used for the microring resonator, then the device structure is simple and easy to manufacture, but the free spectral range cannot be tuned and the device lacks adaptability to changing network conditions

Engineering Contradiction:
Improvetunability of free spectral rangeVSAvoidcomplexity of mechanical structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the microring resonator mechanically tunable through a MEMS actuator. The actuator changes the radius of the microring from a fixed value to a variable value, enabling the free spectral range to be dynamically adjusted. This transforms the static mechanical dimension into a dynamic parameter that can be tuned to adapt to different network conditions and channel spacings.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the microring radius is made variable to enable FSR tuning, then the adaptability to different channel spacings is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveadaptability to channel spacingVSAvoidease of manufacturing
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent replaces complex mechanical tuning systems with a MEMS (Micro-Electro-Mechanical System) actuator. The MEMS device uses electrostatic forces to actuate the microring, providing precise control with minimal mechanical complexity. This substitution of mechanical systems with micro-electromechanical systems simplifies the overall manufacturing process while maintaining the ability to tune the free spectral range.

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

3Productivity

If more wavelengths are used to increase data transmission capacity, then the productivity of the optical network is improved, but filters with smaller FSR are needed which increases device complexity

Engineering Contradiction:
Improvedata transmission capacityVSAvoidcomplexity of filter structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent enables dynamic tuning of the free spectral range to smaller values when high data transmission capacity is required. By using the MEMS actuator to adjust the microring radius, the system can configure filters with smaller FSR to support more wavelengths, thereby increasing productivity. This dynamic adjustment capability allows the network to scale capacity without permanently increasing device complexity.

Inventive Principle:
Principle #15Dynamics

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 tunable microring resonator provides a flexible solution for optical filters and switches, allowing for discrete and pre-defined wavelength spacings, enhancing the adaptability of optical networks and improving the functionality of ring-based wavelength-division multiplexing (WDM) optical switches and frequency comb sources.

Implementation Method 1

a Micro-Electro-Mechanical System (MEMS) adjustable to optically couple at least a first end of the primary waveguide with a first respective end of a selected secondary waveguide thereby allowing light to circulate within the tunable microring resonator

Methodology Applied
Scientific EffectOptical coupling:

Implementation Method 2

allowing light to circulate within the tunable microring resonator

Methodology Applied
Scientific EffectOptical resonance: Resonance

Data Source

PatentEP3387473B1Tunable microring resonator
Publication Date: 2020.02.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3387473B1 patent drawingFigure 1
  • EP3387473B1 patent drawingFigure 2A
  • EP3387473B1 patent drawingFigure 2B

AI summary

The disclosure relates to a tunable microring resonator, comprising a primary waveguide having first and second ends, a plurality of secondary waveguides each having a different length and each having first and second ends and a Micro-Electro- Mechanical System (MEMS) adjustable to optically couple at least a first end of the primary waveguide with a first respective end of a selected secondary waveguide thereby allowing light to circulate within the tunable microring resonator.