THZ-IMAGING Executive summary
Executive summary
THz domain spectroscopy probes the vibrational and rotational modes of molecules. Due to this property, the molecular structure of the analyzed samples can be determined from the emitted or absorbed THz radiation. Additionally, given the weak energy of far-infrared quanta, these radiations are not harmful to the living world.
From these two reasons alone, the THz range of electromagnetic spectrum is associated today with two major research directions:
- Space, by observation of chemical composition of the atmosphere and surface of comets and planets, including the Earth;
- Defense, by identification of hazardous substances of interest, home defense and remote imaging of hidden dangerous objects.
The central objective of the project is to develop a THz range Image Spectrometer, incorporating Digital Micromirror Device (DMD) hardware and Compressive Sensing (CS) and Hadamard Spectrometry (HS) techniques.
For this purpose, the following up to date methods are applied during the project:
- Hadamard spectroscopy;
- Numerical imaging with spatial multiplexing;
- DMD for spatial modulation;
- CS for image reconstruction.
Due to technological advance, it becomes feasible to build, for space applications, an image spectrometer with optimized data acquisition, small mass and dimensions, no moving parts.
Our project research proceeds with this trend and materializes into an experimental model for a THz range image spectrometer, dedicated to space applications. The principle of the instrument is: a THz source (which may be collimated or focused with THz optics) is incident upon specially designed masks. The interaction with the masks, followed by radiation focusing, results in the optical computation of multiplexed image projections. The projections are sensed by a THz detector and transmitted to a computer for processing.
