Campanile probe

Such a probe design allows collecting optical signals, usually photoluminescence (PL) or Raman scattering, with a subwavelength resolution, breaking the diffraction limit.

[1][3] The campanile probe is attached to an optical fiber, which both provides a laser excitation of the studied sample and collects the measured signal.

[4] Campanile probes are typically fabricated as follows: a standard cylindrical single-mode optical fiber is etched with hydrofluoric acid to create a conical tip with a radius of ca.

Then a square pyramid is carved on the tip using focused ion beam (FIB) milling, and its two facets are coated with a metal by shadow evaporation.

[3] Alternative fabrication method uses nanoimprint lithography to replicate campanile pyramid from a mold.

SEM image of a campanile probe. [ 1 ]
SEM image of a campanile probe. [ 1 ]
False-color SEM image of the Campanile near-field probe fabricated on the edge of an optical fiber using nanoimprint
False-color SEM image of the Campanile near-field probe fabricated on the edge of an optical fiber using nanoimprint. [ 2 ]
Comparison of photoluminescence maps recorded from a molybdenum disulfide flake using a campanile probe (top) and conventional confocal microscopy (bottom). Scale bars: 1 μm. [ 1 ]