WGM Resonator Packaging With Adjustable Fiber Coupling Stability

Solution Overview

Problem

Existing packaging methods for tapered fiber-coupled microresonators suffer from low mechanical stability and degradation of the Q factor, while immersion in UV-curable glue limits sensitivity to environmental changes.

Innovation Solution

A packaging technique using an adjusting screw to adjust the coupling efficiency by varying the effective coupling length between the WGM resonator and tapered fiber, allowing for modulation of transmission power and loaded Q factor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If UV-curable glue is used to immerse the coupling region, then mechanical stability is improved, but Q factor deteriorates and sensitivity to environmental changes is reduced

Engineering Contradiction:

Improvemechanical stabilityVSAvoidQ factor

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The packaging structure is segmented into distinct functional zones: a first region containing the WGM resonator with evanescent field exposure for sensing, and a second region containing the tapered fiber coupling structure. This segmentation allows the resonator to maintain Q factor by exposing its evanescent field to the environment while the fiber coupling region provides mechanical stability through the UV-curable glue, thus resolving the contradiction between mechanical stability and Q factor maintenance.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If UV-curable glue is used to immerse the coupling region, then mechanical stability is improved, but sensitivity to environmental changes deteriorates

Engineering Contradiction:

Improvemechanical stabilityVSAvoidsensitivity to environmental changes

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The packaging structure is segmented into distinct functional zones: a first region containing the WGM resonator with evanescent field exposure for sensing, and a second region containing the tapered fiber coupling structure. This segmentation allows the resonator to maintain Q factor by exposing its evanescent field to the environment while the fiber coupling region provides mechanical stability through the UV-curable glue, thus resolving the contradiction between mechanical stability and Q factor maintenance.

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If clamping the TF at two points close to the microresonator is used, then ease of operation is improved, but mechanical stability deteriorates

Engineering Contradiction:

Improvecoupling adjustment capabilityVSAvoidmechanical stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

A packaging structure serving as an intermediary platform is introduced, which holds both the WGM resonator and tapered fiber. The packaging includes a first region for the resonator and a second region for the fiber coupling, allowing mechanical stability through proper mounting while enabling coupling adjustment through movable components within the packaged structure, thus resolving the contradiction between ease of operation and mechanical stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Provides stable coupling with adjustable efficiency, maintaining sensitivity to environmental interactions and reducing optical losses.

Implementation Method 1

Coupling light to WGM resonators may be achieved via evanescent coupling using a prism, or a tapered fiber (TF)

Methodology Applied

Scientific EffectEvanescent coupling:

Data Source

PatentUS12487416B2Packaging of whispering gallery mode resonators with adjustable coupling to an optical fiber

Publication Date: 2025.12.02 STATE OF ISRAEL - SOREQ NUCLEAR RES CENT

AI summary

A method includes coupling an optical whispering gallery mode (WGM) resonator to an optical fiber by placing the optical fiber on the WGM resonator such that a contact portion of the optical fiber contacts the WGM resonator and two non-contact portions of the optical fiber extend beyond the contact portion, coupling the non-contact portions to locking screws, and adjusting positions of the locking screws to change a dimension of the contact portion.