Two-Channel Imaging Spectrometer Shared Optics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging spectrometers are unable to perform hyperspectral imaging in two different, well-separated spectral bands, limiting their ability to analyze certain features of a scene, such as the combination of visible and thermal information.
Innovation Solution
A two-channel spectrometer design using shared reflective-only optics with separate dispersive elements and imaging detectors for each wavelength band, minimizing weight and size by eliminating the need for duplicate bulky components and refractive optics, allowing for simultaneous hyperspectral imaging in disjoint spectral bands like 0.5-5 micrometers and 7.5-12.5 micrometers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate optical systems are used for each spectral band, then spectral imaging capability in multiple bands is achieved, but weight and size of the instrument increase
Solution Approach 1:
The patent combines two separate spectral imaging channels into a single integrated optical system. The shared objective lens and beam splitter allow both spectral bands (0.5-5 μm and 7.5-12.5 μm) to be imaged simultaneously through a common optical path, eliminating the need for duplicate heavy optical components and reducing overall instrument weight.
Solution Approach 2:
The objective lens is designed with multi-functional capability to handle both short-wave (0.5-5 μm) and long-wave (7.5-12.5 μm) spectral bands. This universal optical element performs the imaging function for both channels, replacing what would traditionally require separate specialized optics for each band, thereby reducing total instrument mass.
2Adaptability or versatility
If separate optical systems are used for each spectral band, then spectral imaging capability in multiple bands is achieved, but volume of the instrument increases
Solution Approach 1:
The patent combines two separate spectral imaging channels into a single integrated optical system. The shared objective lens and beam splitter allow both spectral bands (0.5-5 μm and 7.5-12.5 μm) to be imaged simultaneously through a common optical path, eliminating the need for duplicate heavy optical components and reducing overall instrument weight.
Solution Approach 2:
The optical design nests the second spectral channel within the first channel's optical path. The beam splitter divides the incoming light from the shared objective lens into two separate detection paths, allowing both imaging systems to coexist in a compact configuration where one system is effectively nested within the overall optical architecture.
3Reliability
If refractive optics are used, then optical performance is achieved, but wavelength-dependent degradation occurs
Solution Approach 1:
The patent replaces refractive optical elements (lenses) with reflective optical elements (mirrors) in the form of a reflective triplet. This substitution eliminates wavelength-dependent chromatic aberration and other refractive effects, providing consistent optical performance across both spectral bands without the degradation inherent in refractive systems.
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 analysis of features not possible with existing systems by providing high-resolution images and spectral information in two disjoint spectral bands, while minimizing the instrument's weight and size, thus enhancing its capability and practicality for various applications.
Implementation Method 1
The shared double-pass all-reflective optical form receives the first wavelength and the second wavelength from the first and second slits, respectively, and has a reflective optical form output that includes a collimated first wavelength output and a collimated second wavelength output
Implementation Method 2
A first dispersive element receives the collimated first wavelength output and produces a first dispersed output
Implementation Method 3
A second dispersive element receives the collimated second wavelength output and produces a second dispersed output
Implementation Method 4
There is a first imaging detector at the first location
Implementation Method 5
a second imaging detector at the second location
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A two-channel spectrometer (20) has a shared objective (22) and a pair of slits (34, 40) at a common image plane (46). Each of the slits (34, 40) receives a portion of the output beam (22) of the shared objective (22) and is optimized for transmitting different wavelengths. A shared double-pass reflective triplet (48) receives the output beams of the slits. The output of the reflective triplet (48) is incident upon a beamsplitter (62), which sends a collimated first reflective triplet output (52) of a first wavelength to a first dispersive element (64), and a collimated second reflective triplet output (54) of a second wavelength to a second dispersive element (70). The outputs (66, 72) of the dispersive elements (64, 70) are directed back to the beamsplitter (62) and the reflective triplet (48) to imaging detectors (76, 78) located at two different locations of the common image plane (46).