Phase grating design for a dual-band snapshot imaging spectrometer

Area of Science:

• Optics and Photonics
• Infrared Spectroscopy
• Image Processing

Background:

• Infrared spectral features are crucial for identifying threat objects.
• Dual-band focal-plane arrays (FPAs) integrate midwave and long-wave photodetectors for enhanced spectral information.
• Computed-tomography imaging spectrometers (CTIS) excel at producing hyperspectral images within a single spectral band.

Purpose of the Study:

• To improve spatial target discrimination by combining dual-band FPAs with hyperspectral imaging.
• To develop a system capable of simultaneously acquiring hyperspectral data cubes in two infrared bands.
• To design novel computer-generated hologram dispersers for dual-band CTIS applications.

Main Methods:

• Development of two-dimensional, surface-relief, computer-generated hologram dispersers.
• Integration of hologram dispersers with dual-band FPAs and CTIS.
• Simultaneous acquisition of hyperspectral data in midwave and long-wave infrared bands.

Main Results:

• The designed hologram dispersers enable simultaneous image information capture in two distinct infrared bands.
• This approach facilitates the simultaneous production of two hyperspectral data cubes.
• Enhanced spatial target discrimination is achieved by combining dual-band FPAs with CTIS.

Conclusions:

• The developed hologram dispersers are effective for dual-band hyperspectral imaging.
• This technology significantly enhances target discrimination capabilities in infrared sensing.
• The system offers a promising solution for advanced threat object identification.