Dual-Band Pixel Architecture for Lag-Free Spectral Imaging

Solution Overview

Problem

Dual-band photodetectors typically experience a time lag due to temporal interleaving, which can result in the loss of spatial correlation of objects, especially for fast-moving objects, as they switch between detecting light in different spectral ranges.

Innovation Solution

A dual-band imaging device architecture that includes a plurality of pixels with specific absorber and intervening layers, allowing simultaneous detection of light in multiple bands on the same focal plane without time lag, using sequential diodes with the same polarity and compatible with commercially available single-polarity read-out integrated circuits (ROICs).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If temporal interleaving is used to detect light in different spectral ranges, then the device can operate in multiple bands, but time lag occurs and spatial correlation is lost

Engineering Contradiction:

Improvedual-band detection capabilityVSAvoidtime lag between bands

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The pixel is segmented into two independent photodetector elements (first and second photodetectors) that can simultaneously detect different spectral bands. Each photodetector has its own absorber layer configured for a specific band, allowing parallel detection without temporal interleaving.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from temporal multiplexing (switching between bands over time) to spatial multiplexing (detecting multiple bands simultaneously at different spatial locations within the same pixel). This dimensional change eliminates time lag while maintaining spectral discrimination.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Device complexity

If temporal interleaving is used for dual-band detection, then device complexity is reduced, but spatial correlation of fast-moving objects is lost

Engineering Contradiction:

Improvephotodetector structureVSAvoidspatial correlation accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The pixel is segmented into two independent photodetector elements (first and second photodetectors) that can simultaneously detect different spectral bands. Each photodetector has its own absorber layer configured for a specific band, allowing parallel detection without temporal interleving.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from temporal multiplexing (switching between bands over time) to spatial multiplexing (detecting multiple bands simultaneously at different spatial locations within the same pixel). This dimensional change eliminates time lag while maintaining spectral discrimination.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Loss of time

If separate pixels are used for different bands, then simultaneous detection is achieved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvedetection simultaneityVSAvoidpixel array fabrication

Core Design Contradiction:

Loss of timeVSEase of manufacture

Solution Approach 1:

Two separate photodetector pixels are merged into a single pixel structure with shared components (electrodes, substrate, encapsulation). The first and second photodetectors share common structural elements while maintaining independent absorber layers, simplifying manufacturing compared to fabricating separate pixel arrays.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The pixel structure is designed with multi-functionality, where a single pixel performs both first-band and second-band detection through its two photodetectors. This universal design reduces manufacturing complexity compared to producing separate specialized pixels for each band.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables simultaneous detection of light in multiple spectral bands without time lag, maintaining spatial correlation of objects, even for fast-moving ones, and can utilize existing single-polarity ROICs for efficient operation.

Implementation Method 1

A dual-band photodetector or imager is a device that detects or responds to incident light by using the photoelectric effect of absorbed individual photons

Methodology Applied

Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentUS20240088194A1Simultaneous dual-band systems and methods

Publication Date: 2024.03.14 ATTOLLO ENGINEERING LLC

AI summary

The present disclosure is directed generally to simultaneous dual-band systems and methods. A dual-band system as disclosed herein includes a plurality of pixels. Each pixel comprising a first absorber layer; a first intervening layer located adjacent the first absorber layer; a second absorber layer located adjacent to the first intervening layer; and a second intervening layer located adjacent to the second absorber layer. The plurality of pixels includes a first subset of pixels for detecting light in a first band and a second subset of pixels for detecting light in a second band. Carriers created in the first absorber layer of the first subset of pixels are collected via the first contact layer. Carriers created in the second absorber layer of the second subset of pixels are collected via the second contact layer and carriers created in the first absorber layer remain uncollected.