2019/03/14 by Maria C. Giordano, Leonardo Viti, Giordano, Maria C. +5
Physics and Astronomy · #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Optics (physics.optics) #physics.ins-det #physics.optics
paper · pdf · doi:10.48550/arxiv.1903.06200
arxiv created 2019/03/14 · arxiv updated 2019/03/18
Imaging applications in the terahertz (THz) frequency range are severely restricted by diffraction. Near-field scanning probe microscopy is commonly employed to enable mapping of the THz electromagnetic fields with sub-wavelength spatial resolution, allowing intriguing scientific phenomena to be explored such as charge carrier dynamics in nanostructures and THz plasmon-polaritons in novel 2D materials and devices. High-resolution THz imaging, so far, has been relying predominantly on THz detection techniques that require either an ultrafast laser or a cryogenically-cooled THz detector. Here, we demonstrate coherent near-field imaging in the THz frequency range using a room-temperature nanodetector embedded in the aperture of a near-field probe, and an interferometric optical setup driven by a THz quantum cascade laser (QCL). By performing phase-sensitive imaging of strongly confined THz fields created by plasmonic focusing we demonstrate the potential of our novel architecture for high-sensitivity coherent THz imaging with sub-wavelength spatial resolution.