Local Reconstruction for Three Dimensional Terahertz Imaging Using a CW Quantum Cascade Laser

Three-dimensional terahertz imaging using swept-frequency feedback interferometry with a quantum cascade laser.

We demonstrate coherent three-dimensional terahertz imaging by frequency modulation of a quantum cascade laser in a compact and experimentally simple self-mixing scheme. Through this approach, we can realize significantly faster acquisition rates compared to previous schemes employing longitudinal mechanical scanning of a sample. We achieve a depth resolution of better than 0.1 μm with a power ...

Coherent three-dimensional terahertz imaging through self-mixing in a quantum cascade laser

Resonant-phonon terahertz quantum-cascade laser operating at 2.1 THz (/spl Lambda///sup ~/sub _//141/spl mu/m) - Electronics Letters

The development of quantum-cascade lasers (QCLs) at 2.1 THz (l’ 141 mm), which is the longest wavelength QCL to date without the assistance of magnetic fields, is reported. This laser uses a structure based on resonant-phonon depopulation, and a metal–metal waveguide to obtain high modal confinement with low waveguide losses. Lasing was observed up to a heatsink temperature of 72 K in pulsed mo...

Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser.

We report diffuse reflection imaging in air of concealed powdered samples using a terahertz quantum cascade laser. The sensitivity of the detection scheme to sub-surface absorption within samples is confirmed using fully-characterized powdered admixtures of polystyrene and polymethyl methacrylate (PMMA). Measurements of the backscattering intensity from these samples are then used in conjunctio...

Coherent THz imaging using the self-mixing effect in quantum cascade lasers

We demonstrate that the self-mixing effect in terahertz frequency quantum cascade lasers can be used for three-dimensional coherent imaging; swept-frequency interferometry for imaging and materials analysis; and, high-resolution inverse synthetic aperture radar imaging. OCIS codes: (110.6795) Terahertz imaging; (140.5965) Semiconductor lasers, quantum cascade