Waveguide Device With Beam Direction Selective Light Absorber

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Solution Overview

Problem

Current contact image sensors are bulky, low in resolution, and unsuitable for field use, particularly in law enforcement and security applications where immediate identity and background checks are needed, as they lack portability and high resolution capabilities.

Innovation Solution

A portable, high-resolution contact image sensor is developed using parallel optical layers with a stack configuration including a collimated beam of polarized light, switchable Bragg grating arrays, and a waveguiding structure with ITO electrodes, allowing for efficient light transmission and detection, enabling high-resolution imaging in the field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional contact image sensor designs are used, then imaging function is achieved, but device size becomes bulky and portability is reduced

Engineering Contradiction:

Improvesensor sizeVSAvoidportability

Core Design Contradiction:

Volume of moving objectVSEase of operation

Solution Approach 1:

The sensor is divided into multiple functional layers including waveguide layer, Bragg grating layers, and detector layer, allowing each component to be optimized independently and integrated in a compact stacked configuration that reduces overall device volume while maintaining functionality

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple functional layers are nested within each other in a vertical stack configuration, with the waveguide layer containing Bragg grating structures that are themselves layered, creating a compact nested architecture that minimizes device footprint while preserving all necessary imaging functions

Inventive Principle:

Principle #7Nested doll (Nesting)

2Measurement precision

If traditional imaging systems are used, then basic imaging is achieved, but resolution is limited

Engineering Contradiction:

Improveimaging resolutionVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Bragg grating layers are introduced as intermediary optical elements between the waveguide and detector, serving as selective reflectors that enhance image quality and resolution by controlling light propagation paths without requiring complex mechanical or electronic systems

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system utilizes changes in refractive index and optical properties through the Bragg grating structures to control and enhance light reflection and transmission, improving image resolution by manipulating optical parameters rather than increasing mechanical complexity

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If field use requirements are met, then portability is improved, but imaging quality may be compromised

Engineering Contradiction:

Improvefield deployabilityVSAvoidimage quality

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The waveguide layer incorporates switchable Bragg grating elements that can dynamically control light propagation paths, allowing the system to maintain high image quality across varying field conditions while preserving portability through integrated compact design

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The sensor employs composite layered structures combining waveguide materials with Bragg grating materials, creating an integrated system that maintains optical performance and image quality while achieving the compact form factor required for field deployment

Inventive Principle:

Principle #40Composite materials

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 provides a compact, high-resolution imaging capability, suitable for field use, enabling immediate and accurate fingerprint scanning with improved image quality and portability compared to existing technologies.

Implementation Method 1

The waveguide device includes a waveguide core configured to receive light incident at a first surface and propagate the light to a second surface of the waveguide core

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a beam direction selective light absorber comprising a first stack comprising a first alternating sequence of high refractive index material layers and low refractive index material layers and a second stack comprising a second alternating sequence of the high refractive index material layers and the low refractive index material layers

Methodology Applied

Scientific EffectSelective absorption: Absorption (EM radiation)

Implementation Method 3

The waveguide device incorporates a grating

Methodology Applied

Scientific EffectDiffraction: Diffraction

Data Source

PatentUS11443547B2Waveguide device incorporating beam direction selective light absorber

Publication Date: 2022.09.13 DIGILENS INC

AI summary

A contact image sensor having an illumination source; a first SBG array device; a transmission grating; a second SBG array device; a waveguiding layer including a multiplicity of waveguide cores separated by cladding material; an upper clad layer; and a platen. The sensor further includes: an input element for coupling light from the illumination source into the first SBG array; a coupling element for coupling light out of the cores into output optical paths coupled to a detector having at least one photosensitive element.