Monolithic Imager Pixel Segmentation for SWIR Wavelength Differentiation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional imagers struggle to differentiate between various wavelengths within the short wavelength infrared (SWIR) spectrum, requiring bulk filters that increase complexity and cost, and cannot accurately represent a scene at a single point in time or easily scale to detect multiple ranges of wavelengths.
Innovation Solution
A monolithic imager design where different pixels within the imaging array detect distinct ranges of wavelengths in the SWIR spectrum, using semiconductor materials for filters and photodetectors, eliminating the need for bulk filters and allowing for single-frame, multi-wavelength differentiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional imagers use bulk filters to differentiate wavelengths in the SWIR spectrum, then wavelength differentiation capability is improved, but device complexity and cost increase
Solution Approach 1:
The imaging array is segmented into multiple pixel types, where each pixel type is configured with specific photodetector materials and filters to detect different wavelength ranges in the SWIR spectrum. This segmentation eliminates the need for external bulk filters while achieving wavelength differentiation through the pixel array itself.
Solution Approach 2:
The imaging array is designed to perform multiple functions simultaneously: it detects different wavelength ranges, produces separate images for each wavelength range, and does so in a single frame without requiring additional optical components. Each pixel contributes to multiple wavelength detections through the array's overall functionality.
2Adaptability or versatility
If conventional imagers use bulk filters for wavelength detection, then wavelength range detection is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines multiple detection functions into a single integrated imaging array structure. Different photodetector materials (silicon, germanium, indium gallium arsenide) are merged within the same device to detect different wavelength ranges, eliminating the need for separate detectors and bulk filters, thereby reducing manufacturing complexity and cost.
Solution Approach 2:
Different regions of the imaging array are assigned different photodetector materials and filter configurations optimized for specific wavelength ranges. This local quality approach allows each pixel type to be tailored for its specific detection function while maintaining overall system integration and manufacturability.
3Adaptability or versatility
If conventional imagers capture multiple wavelength ranges sequentially, then wavelength differentiation is improved, but imaging speed decreases
Solution Approach 1:
The imaging array is pre-configured with multiple pixel types that simultaneously detect different wavelength ranges during a single exposure. This preliminary configuration of diverse pixel types within the array enables parallel wavelength detection, eliminating the need for sequential filtering and multiple frame capture.
Solution Approach 2:
The patent transitions from temporal multiplexing (sequential wavelength detection over time) to spatial multiplexing (simultaneous wavelength detection across different pixel locations). By adding the spatial dimension of pixel-type differentiation, the system achieves wavelength differentiation without sacrificing imaging speed.
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 the production of images that differentiate between multiple ranges of wavelengths within the SWIR spectrum in a single frame, simplifying the imager design, reducing complexity, and improving imaging characteristics such as detection and noise performance.
Implementation Method 1
The photodetectors are sensitive to (i.e., detect) incoming radiation and produce an output signal (referred to as a 'photoresponse') based on the detected radiation.
Implementation Method 2
a filter disposed between the photodetector and the metallization layer and configured to block a first range of wavelengths, comprising wavelengths greater than 700 nanometers, of the radiation incident thereon from reaching the photodetector
Data Source
AI summary
Imagers, pixels, and methods of using the same are disclosed for imaging in various spectra, such as visible, near infrared (IR), and short wavelength IR (SWIR). The imager may have an imaging array having pixels of different types. The different types of pixels may detect different ranges of wavelengths in the IR, or the SWIR, spectra. The pixels may include a filter which blocks some wavelengths of radiation in the IR spectrum while passing other wavelengths. The filter may be formed of a semiconductor material, and therefore may be easily integrated with a CMOS pixel using conventional CMOS processing techniques.