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.
Differential Near-Field Scanning Optical Microscopy with THz quantum cascade laser sources
XU, Jihua;PINGUE, Pasqualantonio;A. TREDICUCCI;BELTRAM, Fabio;
2009
Abstract
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.File in questo prodotto:
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