Dielectric Microlens with High-Index Insert for Near-Field Focusing

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Solution Overview

Problem

Existing technologies face challenges in achieving efficient light focusing and focal spot shifting at the nanoscale, particularly due to the diffraction limit and complexity of fabrication techniques.

Innovation Solution

A new optically-transparent device comprising a main part of dielectric material with a specific refractive index and at least one dielectric insert with a higher refractive index, forming an inhomogeneous microstructure that generates a high-intensity nanojet beam by recombining nanojet beams from different edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional optical lenses are miniaturized to subwavelength scale, then the device size is reduced, but diffraction limit prevents effective focusing

Engineering Contradiction:
Improvelens sizeVSAvoidfocusing capability
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent changes the refractive index parameter by introducing a high-refractive-index dielectric insert (n3 > n2) into the main dielectric material (n2), creating an inhomogeneous microstructure that enables subwavelength focusing despite the reduced lens size

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite dielectric materials with different refractive indices (main material with n2 and insert with n3) to create a structured microstructure that overcomes the diffraction limit while maintaining miniaturization

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If planar lenses are designed with sophisticated structures to improve focusing performance, then focusing capability is enhanced, but fabrication complexity increases

Engineering Contradiction:
Improvefocusing capabilityVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the lens into a main dielectric material portion and a separate high-refractive-index insert portion, allowing independent optimization of each part while maintaining overall simplicity compatible with standard fabrication techniques

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by concentrating the high-refractive-index material in specific regions (the insert) rather than using it throughout the entire lens, enabling enhanced focusing at the focal spot while keeping the overall structure simple

Inventive Principle:
Principle #3Local quality

3Productivity

If dielectric inserts with higher refractive index are introduced to enhance field intensity, then focusing efficiency is improved, but device structure becomes more complex

Engineering Contradiction:
Improvefocusing efficiencyVSAvoidmicrostructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements the nested doll principle by placing the high-refractive-index dielectric insert inside the main dielectric material, creating a nested structure that enhances focusing efficiency while maintaining compatibility with standard fabrication processes

Inventive Principle:
Principle #7Nested doll (Nesting)

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 proposed device enhances field intensity in the focal spot and allows for controlled focal spot position, achieving improved near-field focusing efficiency and anisotropic performance characteristics.

Implementation Method 1

The microlens with an insert is configured for generating a condensed optical beam in a near field of the microlens

Methodology Applied
Scientific EffectPhotonic nanojet:

Implementation Method 2

The first element comprises at least partially a second element having a second refractive index value greater than the first index value

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3861400B1Device for near-field focusing and beam forming
Publication Date: 2025.04.23 INTERDIGITAL CE PATENT HOLDINGS SAS
  • EP3861400B1 patent drawingFigure 1(a)~2(b)
  • EP3861400B1 patent drawingFigure 3~4
  • EP3861400B1 patent drawingFigure 5(a)~5(c)

AI summary

An optically-transparent device (100) is disclosed which comprises a main part (10) of dielectric material having a refractive index n2, said device being configured for forming a field intensity distribution in a near zone of said device from electromagnetic waves incidentally illuminating said device, when said device is embedded into a dielectric material having a refractive index n1 lower than said refractive index n2. Said device (100) further comprises at least one insert (11) of dielectric material having a refractive index n3 higher than said refractive index n2, said at least one insert being at least partly inserted into said main part, said refractive index n1 being different from said refractive index n3, and wherein Formula (I) with W2 being a half width of said insert and Formula (II), Formula (III) with W1 being a half width of said main part and Formula (IV), with λ being the wavelength of the electromagnetic wave propagating in the dielectric material having refractive index n1.