Demonstration of a computed-tomography imaging spectrometer using a computer-generated hologram disperser

Area of Science:

• Optics and Photonics
• Spectroscopy
• Computational Imaging

Background:

• Traditional imaging spectrometers often face limitations in speed and data acquisition.
• Developing advanced techniques for simultaneous spatial and spectral data collection is crucial for applications like flash spectral imaging.

Purpose of the Study:

• To construct and validate a novel computed-tomography imaging spectrometer.
• To utilize a phase-only computer-generated hologram (CGH) array illuminator as a disperser for enhanced spectral resolution and efficiency.

Main Methods:

• Designed a CGH array illuminator to ensure uniform spectral diffraction efficiency across multiple orders and minimize higher-order diffraction.
• Employed computed-tomography techniques for reconstructing a three-dimensional (x, y, lambda) image cube from multiplexed 2D spatial and spectral data.
• Integrated the CGH disperser within a computed-tomography framework for simultaneous data capture.

Main Results:

• The constructed imaging spectrometer successfully collected multiplexed spatial and spectral data.
• The CGH disperser demonstrated nearly equal spectral diffraction efficiency across a 5x5 array of diffraction orders.
• Reconstructed image and spectral-signature data showed favorable comparison with established spectrometric methods.

Conclusions:

• The developed computed-tomography imaging spectrometer is effective for flash spectral imaging.
• The use of a CGH array illuminator as a disperser offers a promising approach for advanced spectrometric measurements.
• This technique provides a viable alternative to existing spectrometric methods for capturing complex spectral information.