We have realized a differential Near-field Scanning Optical Microscope (NSOM) working with subwavelength resolution in the THz spectral region. The system employs a quantum cascade laser emitting at λ ~105 µm as source, and the method, differently from conventional NSOM, involves diffracting apertures with size comparable to the wavelength. This concept ensures a higher signal-to-noise level at the expense of an additional computational step. In the implementation here reported λ/10 resolution has been achieved; present limiting factors are investigated through finite difference time domain simulations.
|Titolo:||Differential Near-Field Scanning Optical Microscopy with THz quantum cascade laser sources|
|Data di pubblicazione:||2009|
|Parole Chiave:||scanning probe microscopy; near field; THz|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1364/OE.17.023785|
|Appare nelle tipologie:||1.1 Articolo in rivista|