Correlated Ghost Imaging for Real-Time THz Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current THz imaging systems are inefficient for real-time detection of concealed weapons and explosives due to their reliance on single source and detector pairs, which take minutes to acquire images and lack sufficient spatial resolution, and require large areas for good detail, making them unsuitable for practical security screening.
Innovation Solution
A method and system utilizing conventional optics and detectors, where photon fields with different wavelengths are sent through a chopper and wavelength-selective mirror, enabling a visible photon array detector to register images of THz-illuminated scenes, with optional up-conversion or down-conversion crystals for enhanced resolution and raster scanning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single THz source and detector pair is scanned across the object space, then the system can detect concealed weapons and explosives, but the image acquisition time becomes excessively long (typically minutes)
Solution Approach 1:
The patent segments the detection function by separating the THz illumination source from the detector array. Multiple detectors simultaneously capture THz information from different spatial positions, eliminating the need for mechanical scanning while maintaining detection capability across the entire object space.
Solution Approach 2:
The patent transitions from a single-point detection approach (1D scanning) to a multi-point simultaneous detection approach (2D/3D parallel detection). By arranging detectors in an array configuration, the system captures spatial information across multiple dimensions simultaneously, dramatically reducing acquisition time.
2Measurement precision
If a large area detector array is used to obtain good spatial resolution, then the spatial details improve, but the system requires a large detector area which increases complexity and cost
Solution Approach 1:
The patent introduces a lens or optical system as an intermediary between the THz source and detector array. This optical element focuses and directs THz radiation onto the detector elements, enabling high spatial resolution to be achieved with a more compact detector arrangement rather than requiring a large detector area.
Solution Approach 2:
The patent changes the spatial distribution and focusing parameters of the THz beam using optical elements. By controlling the beam convergence and detector positioning, the system achieves high spatial resolution through optimized parameter configuration rather than simply increasing detector area.
3Measurement precision
If the THz beam size is reduced to achieve good spatial resolution, then the resolution improves, but the imaged area decreases
Solution Approach 1:
The patent segments the imaging process by using multiple detectors positioned at different locations, each receiving a focused portion of the THz beam. This allows the system to maintain a small effective beam size for high resolution at each detector while collectively covering a large imaged area through the array configuration.
Solution Approach 2:
The patent resolves the trade-off by transitioning from a single-beam approach to a multi-beam or distributed beam approach. Multiple detectors simultaneously receive focused THz energy from different angular positions, enabling high spatial resolution in one dimension while maintaining a large field of view in other dimensions.
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 sharper images of concealed weapons and explosives by coupling a non-imaging THz receiver with a visible-photon array detector, allowing for real-time imaging through clothing and identifying chemicals with unique spectral fingerprints in the THz range, while being safe and efficient.
Implementation Method 1
Photon fields with two different wavelengths can be sent through a chopper
Implementation Method 2
Photon fields with two different wavelengths can be sent through a chopper and towards a wavelength-selective mirror
Implementation Method 3
A beam with a wavelength in the visible or IR range is sent toward a visible photon array detector
Implementation Method 4
light beams with wavelengths in the THz range can be sent towards a target, which are reflected and/or absorbed by objects in the target. The reflected or transmitted light continues on through an optional filter to remove background light, then into a non-imaging detector
Implementation Method 5
THz radiation can detect concealed weapons since many non-metallic, non-polar materials are transparent to THz radiation
Implementation Method 6
An up-conversion crystal can be placed in the detector path for detecting THz images with the visible photon array detector
Implementation Method 7
a down-conversion crystal can be used to generate the photon fields with two different wavelengths
Data Source
AI summary
A method and system for detecting concealed weapons and explosives by imaging THz scenes using conventional optics and detectors is provided. Photon fields with two different wavelengths can be sent through a chopper and towards a wavelength-selective mirror. A light beam with a wavelength in the visible or IR range is sent toward a visible photon array detector. Similarly, light beams with wavelengths in the THz range can be sent towards a target, which are reflected and/or absorbed by objects in the target. The reflected or transmitted light continues on through an optional filter to remove background light, then into a non-imaging detector. The visible photon array detector can be coupled with the non-imaging detector, which will register an image of the scene that is illuminated by the THz photons.