Hyperspectral Imager Using Dual Frequency Combs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional imaging systems become complex and require frequency filtering or scanning components when capturing detailed information across a wide range of electromagnetic frequencies, limiting their ability to generate hyperspectral images efficiently.
Innovation Solution
The use of dual frequency combs with offset repetition rates, combined through a beam combiner and split into interrogation and reference beams, which are spatially encoded and used to generate hyperspectral images without the need for frequency filtering or scanning components, employing computational imaging techniques for reconstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional imaging systems use frequency filtering or scanning components to capture detailed information across wide electromagnetic frequency ranges, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes frequency filtering components and frequency scanning components from the conventional hyperspectral imaging system. By using a single-pixel sensor without these components, the system achieves spectral imaging capability while significantly reducing device complexity. The spectral information is obtained through computational methods rather than physical filtering or scanning mechanisms.
Solution Approach 2:
The patent replaces mechanical frequency scanning components with computational imaging techniques. Instead of using moving parts or mechanical filters to scan through different frequencies, the system uses algorithmic processing of spatially modulated measurements to reconstruct spectral information, thereby eliminating mechanical complexity while maintaining spectral resolution.
2Measurement precision
If multiple pixel sensor arrays and frequency scanning components are used to obtain detailed wavelength information, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes multiple pixel sensor arrays from the system, replacing them with a single-pixel sensor. The spectral imaging capability is achieved through computational reconstruction from spatially modulated measurements rather than direct detection by multiple sensors, thereby eliminating the complexity associated with multiple pixel arrays while maintaining spectral information accuracy.
Solution Approach 2:
The patent uses computational methods to create virtual spectral copies from a single-pixel sensor. By spatially modulating the illumination and using algorithmic reconstruction, the system generates spectral information that would traditionally require multiple sensors, effectively creating a computational copy of the spectral data without the physical complexity of multiple pixel arrays.
3Measurement precision
If frequency scanning components are incorporated to achieve hyperspectral imaging, then measurement precision is improved, but productivity decreases
Solution Approach 1:
The patent extracts and removes frequency scanning components from the system. By using a single-pixel sensor with computational reconstruction, the system eliminates the need for time-consuming frequency scanning while maintaining spectral detail capability, thereby significantly improving imaging speed and productivity.
Solution Approach 2:
The patent applies spatial modulation to the illumination pattern before detection. By pre-encoding the spatial information into the illumination pattern and using computational reconstruction, the system obtains spectral information without requiring subsequent frequency scanning steps, thereby accelerating the imaging process while maintaining spectral detail.
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
This approach allows for compact, low-SWAP systems capable of generating hyperspectral images across a wide spectral range, enabling rapid and efficient imaging, including gas detection and materials identification, without the need for complex scanning or filtering, and facilitates real-time image acquisition.
Implementation Method 1
a first frequency comb source for generating a first frequency comb at a first repetition rate; a second frequency comb source for generating a second frequency comb at a second repetition rate that is offset from the first repetition rate
Implementation Method 2
a first beam combiner in optical communication with the first frequency comb source and the second frequency comb source, the first beam combiner for combining the first frequency comb and the second frequency comb to generate a dual frequency comb
Implementation Method 3
a first beam splitter in optical communication with the first beam combiner, the first beam splitter for splitting the dual frequency comb to generate an interrogation beam and a reference beam
Implementation Method 4
a spatial encoder in optical communication with the first beam splitter, the spatial encoder for spatially encoding the reference beam using a set of reference fields to generate an encoded reference beam
Implementation Method 5
a reflective telescope in optical communication with the first beam splitter, the reflective telescope for illuminating a target with the interrogation beam
Implementation Method 6
a collection optic positioned to collect reflected light generated by interaction of the interrogation beam with the target
Implementation Method 7
a second beam combiner in optical communication with the spatial encoder and the collection optic, the second beam combiner for combining the reflected light with the encoded reference beam to generate a combined beam
Implementation Method 8
a detector in optical communication with the second beam combiner, the detector for detecting the combined beam and producing a set of interferograms
Implementation Method 9
a processor configured to generate a hyperspectral digital image of the target using the set of interferograms and the set of reference fields
Data Source
Figure 1A~1B
Figure 2
Figure 3A
AI summary
Systems and methods are disclosed for generating hyperspectral images, which may correspond to a three dimensional image in which two dimensions correspond to a spatial field of view and a third dimension corresponds to a frequency domain absorption spectrum. Disclosed systems and methods include those employing dual optical frequency comb Fourier transform spectroscopy and computational imaging for generation of hyperspectral images. Such a combination advantageously allows for imaging systems to exhibit low size, weight, and power, enabling small or handheld sized imaging devices.