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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Generation of Bessel beams using a terahertz quantum cascade laser
M U Shaukat1, P Dean, S P Khanna
1School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK.
Optics Letters
|April 3, 2009
Summary
We generated Bessel beams using polytetrafluoroethene conical lenses and a quantum cascade laser. These beams maintain their size over long distances, offering an alternative to parabolic reflectors for terahertz imaging.
Area of Science:
- Optics and Photonics
- Terahertz Science and Technology
Background:
- Bessel beams are non-diffracting beams with unique propagation characteristics.
- Terahertz (THz) imaging requires efficient beam generation and manipulation for various applications.
Purpose of the Study:
- To demonstrate the generation of Bessel beams using novel polytetrafluoroethene (PTFE) conical lenses.
- To compare the performance of these PTFE lenses with traditional parabolic reflectors for THz applications.
Main Methods:
- Utilized a quantum cascade laser emitting at 2.8 THz.
- Employed polytetrafluoroethene conical lenses to generate Bessel beams.
- Characterized beam propagation and power transport properties.
Main Results:
- Successfully generated Bessel beams with a central spot maintaining size beyond the Rayleigh range.
- Demonstrated that PTFE conical lenses can produce Bessel beams with comparable or superior power transport to parabolic reflectors.
- Showcased the potential for large depth of focus and efficient radiation coupling.
Conclusions:
- Polytetrafluoroethene conical lenses are a viable and attractive alternative to parabolic reflectors for THz applications.
- These lenses enable Bessel beam generation suitable for terahertz imaging requiring extended focal depth or precise coupling.
