MEMS Tunable Optical Cavity for Low-Power Wavelength Control

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Solution Overview

Problem

Existing tunable optical cavities face challenges in tuning emission characteristics of lasers at low electrical power without generating heat, often resulting in unwanted shifts and hopping of emission lasing wavelength due to thermal crosstalk.

Innovation Solution

A tunable optical cavity is designed with a tunable phase shifter and a tunable optical coupler, capable of adjusting the effective cavity length and optical coupling without heat generation, using MEMS-based actuators that consume low electrical power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If thermal method is used for cavity tuning, then emission characteristics can be tuned, but high electrical power is consumed and heat is generated

Engineering Contradiction:

Improvetuning capabilityVSAvoidelectrical power consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the thermal tuning method with a mechanical tuning method using MEMS actuators. The actuators physically move the waveguide to change the effective cavity length and resonance wavelength, substituting thermal field effects with mechanical displacement. This eliminates heat generation while maintaining tuning capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the tuning parameter from temperature (thermal method) to physical position (mechanical method). By controlling the position of the waveguide through MEMS actuators, the effective cavity length is directly modified, changing the resonance wavelength without thermal effects. This parameter transformation resolves the contradiction between tuning capability and power consumption.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If thermal method is used for cavity tuning, then emission wavelength can be adjusted, but unwanted shift and hopping of emission lasing wavelength occurs due to thermal crosstalk

Engineering Contradiction:

Improvewavelength adjustmentVSAvoidwavelength stability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces thermal field-based wavelength adjustment with mechanical field-based adjustment. The MEMS actuator provides precise, controlled mechanical displacement of the waveguide, eliminating thermal crosstalk that causes unwanted wavelength shifts and hopping. This mechanical approach ensures wavelength stability while maintaining adjustment capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If thermal method is used for cavity tuning, then resonance wavelength can be tuned, but heat generation occurs

Engineering Contradiction:

Improveresonance tuningVSAvoidheat generation

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent substitutes thermal field effects with mechanical field effects for resonance tuning. The MEMS actuator mechanically displaces the waveguide to change the effective cavity length, directly tuning the resonance wavelength without generating heat. This mechanical substitution eliminates the heat generation problem while preserving resonance tuning functionality.

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

The solution enables precise tuning of emission characteristics at low electrical power, preventing unwanted shifts and hopping of emission lasing wavelength, and achieving efficient operation with minimal power consumption.

Implementation Method 1

a first actuator that moves one of the cavity waveguide or the perturbation waveguide in a first moving direction as a first movable waveguide

Methodology Applied

Scientific EffectMEMS-based actuation: Microelectromechanical Systems

Implementation Method 2

a tunable phase shifter configured to shift a phase of light proceeding the cavity waveguide

Methodology Applied

Scientific EffectPhase shift: Phase Modulation

Implementation Method 3

an optical coupling occurs between the first waveguide portion and the second waveguide portion

Methodology Applied

Scientific EffectOptical coupling: Waveguide (optics)

Data Source

PatentUS20250067971A1Tunable optical cavity and optoelectronic system employing the same

Publication Date: 2025.02.27 KOREA ADVANCED INST OF SCI & TECH

AI summary

A tunable optical cavity and an optoelectronic system employing the same are disclosed. The tunable optical cavity includes a waveguide provided to include first and second optical coupler loops, and a cavity waveguide therebetween, a tunable phase shifter that shifts a phase of light proceeding the cavity waveguide, and a controller. The tunable phase shifter includes a perturbation waveguide arranged in parallel with a straight waveguide portion of the cavity waveguide and a first actuator that moves one of the cavity waveguide and the perturbation waveguide in a first moving direction as a first movable waveguide. The controller controls a driving signal applied to the first actuator to adjust an effective cavity length between the first and second optical coupler loops. Each of the first and second optical coupler loops includes a first waveguide portion and a second waveguide portion arranged in parallel with each other to occur an optical coupling therebetween.