2 research outputs found
Terahertz Nanofocusing with Cantilevered Terahertz-Resonant Antenna Tips
We developed THz-resonant
scanning probe tips, yielding strongly
enhanced and nanoscale confined THz near fields at their tip apex.
The tips with length in the order of the THz wavelength (λ =
96.5 μm) were fabricated by focused ion beam (FIB) machining
and attached to standard atomic force microscopy (AFM) cantilevers.
Measurements of the near-field intensity at the very tip apex (25
nm radius) as a function of tip length, via graphene-based (thermoelectric)
near-field detection, indicate their first and second order geometrical
antenna resonances for tip length of 33 and 78 μm, respectively.
On resonance, we find that the near-field intensity is enhanced by
one order of magnitude compared to tips of 17 μm length (standard
AFM tip length), which is corroborated by numerical simulations that
further predict remarkable intensity enhancements of about 10<sup>7</sup> relative to the incident field. Because of the strong field
enhancement and standard AFM operation of our tips, we envision manifold
and straightforward future application in scattering-type THz near-field
nanoscopy and THz photocurrent nanoimaging, nanoscale nonlinear THz
imaging, or nanoscale control and manipulation of matter employing
ultrastrong and ultrashort THz pulses