Ring Resonator Higher-Order Modes for TPA-Limited Power Handling

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Solution Overview

Problem

Silicon-based photonic integrated circuits face limitations in power capacity due to non-linear two-photon absorption (TPA) in ring resonators, which restricts the power that can be transmitted through bus waveguides.

Innovation Solution

Designing optical ring resonators with wider geometries to support higher-order modes, such as TE0n modes, coupled efficiently with single-mode bus waveguides to distribute optical power more broadly, thereby reducing peak power within the ring resonators and mitigating TPA effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ring resonators are designed with conventional geometries to maintain single-mode operation, then mode purity is improved, but power handling capacity deteriorates due to TPA limitations

Engineering Contradiction:

Improvemode purityVSAvoidpower handling capacity

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The patent segments the optical mode into two distinct components: a fundamental TE00 mode confined to the bus waveguide and higher-order TE0n modes confined to the ring resonator. This segmentation allows each component to operate in its optimal mode regime, with the bus waveguide maintaining single-mode purity while the ring resonator utilizing higher-order modes for enhanced power handling capacity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different geometric characteristics to different parts of the system: the bus waveguide maintains a narrow geometry optimized for single-mode TE00 operation, while the ring resonator employs a wider geometry that supports higher-order TE0n modes. This local differentiation of geometric properties enables each component to optimize its specific function.

Inventive Principle:

Principle #3Local quality

2Power

If optical power is increased to improve signal strength, then transmission capability is improved, but non-linear absorption increases due to TPA

Engineering Contradiction:

Improveoptical power transmissionVSAvoidnon-linear absorption

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent introduces higher-order modes as an intermediary mechanism that mediates between the input optical power and the non-linear absorption process. By coupling the fundamental TE00 mode from the bus waveguide to higher-order TE0n modes in the ring resonator, the system can transmit higher optical powers while the broader mode distribution reduces the peak intensity that causes TPA.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If ring resonator geometry is widened to support higher-order modes, then power handling capacity is improved, but coupling efficiency with single-mode bus waveguides deteriorates

Engineering Contradiction:

Improvepower handling capacityVSAvoidcoupling efficiency

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent employs parameter changes in the coupling region, specifically varying the waveguide width and introducing tapered transitions between the narrow bus waveguide and wider ring resonator. These parameter variations enable efficient mode coupling while maintaining single-mode operation in the bus waveguide and higher-order mode support in the ring resonator.

Inventive Principle:

Principle #35Parameter changes

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

Enhances the power handling capacity of silicon photonic integrated circuits by allowing higher optical power transmission without inducing non-linear absorption, thus overcoming TPA limitations.

Implementation Method 1

A ring resonator is commonly coupled by evanescent coupling to one or more bus waveguides, wherein the field of a guided optical wave in one bus waveguide is coupled to the ring resonator

Methodology Applied

Scientific EffectEvanescent coupling:

Implementation Method 2

the optical ring waveguide having a second geometrical width wider than first geometrical width and configured to maintain therewithin optical radiation in the given wavelength range in a second optical mode different from the first optical mode

Methodology Applied

Scientific EffectGuided modes: Waveguide (optics)

Implementation Method 3

the optical ring waveguide has a length selected to maintain a standing wave in the second optical mode at one or more resonant wavelengths in the given wavelength range

Methodology Applied

Scientific EffectStanding wave:

Implementation Method 4

a single-mode optical waveguide disposed on the substrate and having a first geometrical width chosen to guide optical radiation in a first optical mode within a given wavelength range through the single-mode optical waveguide

Methodology Applied

Scientific EffectSingle-mode guidance: Waveguide (optics)

Data Source

PatentUS20250231344A1Ring Resonator Supporting High-order Guided Modes

Publication Date: 2025.07.17 MARVELL ASIA PTE LTD

AI summary

An optical device includes a substrate and a single-mode optical waveguide disposed on the substrate and having a first geometrical width chosen to guide optical radiation in a first optical mode within a given wavelength range through the single-mode optical waveguide. An optical ring waveguide is disposed on the substrate and optically coupled to the single-mode optical waveguide, the optical ring waveguide having a second geometrical width wider than first geometrical width and configured to maintain therewithin optical radiation in the given wavelength range in a second optical mode different from the first optical mode.