Multi-Layer Optical Device for Anomalous Dispersion in UV Waveguides

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Solution Overview

Problem

Optical devices at UV wavelengths face strong normal material dispersion, which causes spreading of optical pulses, hindering the generation and sustainment of high-intensity, ultra-short pulses necessary for advanced applications like quantum computing and spectroscopy.

Innovation Solution

A multi-layer optical device design with an anomalous waveguide dispersion is achieved through the 'avoided crossing' behavior of dispersion curves in a layered waveguide structure, where the geometry and material composition of the heterostructure are tailored to obtain a large positive dispersion coefficient, exceeding normal material dispersion, thereby enabling the formation of ultra-short optical pulses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional single-layer optical devices are used at UV wavelengths, then the device structure is simple, but strong normal material dispersion causes spreading of optical pulses

Engineering Contradiction:
Improvedevice structureVSAvoidpulse spreading
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The optical device is divided into multiple layers with different materials (e.g., GaN layer and AlGaN layer) to separate and independently control the dispersion characteristics of each layer, enabling the overall device to achieve anomalous dispersion while maintaining manageable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs composite material structures combining different semiconductor materials (GaN, AlGaN with varying aluminum compositions) to create a multi-layer heterostructure that exhibits anomalous waveguide dispersion, counteracting the normal material dispersion of individual materials

Inventive Principle:
Principle #40Composite materials

2Reliability

If multi-layer heterostructure is designed to achieve anomalous dispersion, then pulse spreading is counteracted, but the device structure becomes complex

Engineering Contradiction:
Improvepulse spreadingVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent systematically varies material composition parameters (aluminum content x in AlxGa1-xN ranging from 0.1 to 0.6), layer thicknesses (e.g., GaN layer 100-300nm, AlGaN layer 200-500nm), and refractive indices to optimize the dispersion characteristics and achieve the desired anomalous dispersion regime

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Different regions of the optical device are assigned different material compositions and structural properties - the GaN layer has one set of optical properties while the AlGaN layer has different properties - allowing each region to contribute differently to the overall dispersion characteristics

Inventive Principle:
Principle #3Local quality

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 design effectively generates and sustains high-intensity, ultra-short optical pulses by counteracting nonlinear dispersion, facilitating efficient four-wave mixing and enabling bright-soliton formation, suitable for applications in quantum computing and spectroscopy.

Implementation Method 1

A multi-layer optical device design with an anomalous waveguide dispersion is achieved through the 'avoided crossing' behavior of dispersion curves in a layered waveguide structure

Methodology Applied
Scientific EffectAnomalous dispersion: Dispersion (of waves)

Implementation Method 2

facilitating efficient four-wave mixing and enabling bright-soliton formation

Methodology Applied
Scientific EffectFour-wave mixing:

Data Source

PatentEP3862809B1Multi-layer optical device exhibiting anomalous dispersion
Publication Date: 2024.05.15 PALO ALTO RESEARCH CENTER INC
  • EP3862809B1 patent drawingFigure 1
  • EP3862809B1 patent drawingFigure 2~3
  • EP3862809B1 patent drawingFigure 4~5

AI summary

An optical device has a first optical layer with a first dispersion response as a first function of wavelength. A second optical layer has a second dispersion response as a function of wavelength that is different than the first function. A separating layer is located between the first and second optical layers and has a lower refractive index than the first layer and the second layer. A thickness of the separating layer is selected such that the first and second dispersion responses combine to create an anomalous dispersion about a target wavelength. The anomalous dispersion results in the optical device emitting a wideband coherent optical output about the target wavelength in response to an optical input at the target wavelength.