PHYSICS AND TECHNOLOGY OF LIGHT AT THE NANOSCALE
1. In the THz frequency range, security, sensing, detection remain elusive. These applications aim our research to the development of new photonic and electronic technologies and new material systems, as 1D semiconductor nanowires or 2D materials.
2. Near-field imaging with THz waves is a powerful technique in nanophotonics. Spatial resolution beyond the diffraction limit can be achieved by collecting waves in the near-field. We investigate both aperture-based near-field collection as well as scattering-type scanning THz near-field microscopy (s-SNOM), introducing novel concepts and techniques.
3. High-resolution spectroscopy and ultrafast tomography in the far-infrared (FIR) require systems with targeted sensitivity: we focus on the developments of high power 2D and 1D THz lasers, microcavity-coupled continuous tunable and mode-locked sources and waveguide adapters for efficient out-coupling. Furthermore, new sources with the potential to operate at room temperature are being pursued based on intersubband polaritons, both in the mid-infrared (MIR) and FIR.
4. Coupling THz sources with mechanical nano-structures through optical forces is a novel approach to add advanced functionalities to QCLs working in the FIR. Various possibilities from linewidth stabilization to phase locking are currently investigated considering mechanical elements embedded in the laser cavity itself.
5. The investigation of strain-engineered 2D materials offers new perspectives for the control of the quantization of electron states. Suitable strain profiles have the same effect of a magnetic field and induce tunable gaps that could be exploited to implement Landau-level lasers or Faraday rotators with no need for real magnets.
6. Near-infrared radiation offers opportunities to exploit optical forces in ultra-small volume electromagnetic modes. This miniaturization paves the way to normal vibrational modes around tens of GHz, enabling a full control and harnessing of phonons as a novel channel for on-chip telecom.
7. Quantum communication theory: the aim is to study the ultimate rates of information transmission which one can obtain exploiting quantum systems as information carriers.
8. Subwavelength control of light in semiconductor nanowires.
Some of the main efforts planned for 2017-2019 are listed below:
1. Nanodetectors
2. Near-field far infrared photonics
3. Photonic Engineering of Terahertz Quantum Cascade Lasers.
4. Electromechanical Terahertz emitters.
5. Strain-engineering for photonics.
6. Optomechanics for phonon-based telecommuncations.
7. Quantum detectors for optical signals.
8. Subwavelength control of light in semiconductor nanowires.
9. Optical passive devices at THz frequencies.
10. Quantum metrology with THz quantum cascade lasers.