title: Differential near-field scanning optical microscopy with THz quantum cascade laser sources.
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 lambda approximately 105 microm 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 lambda/10 resolution has been achieved; present limiting factors are investigated through finite difference time domain simulations.
authors.affiliation: NEST, CNR-INFM and Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy. riccardo.deglinnocenti@sns.it
authors.forename: R
authors.initials: R
authors.lastname: Degl'Innocenti
authors.forename: M
authors.initials: M
authors.lastname: Montinaro
authors.forename: J
authors.initials: J
authors.lastname: Xu
authors.forename: V
authors.initials: V
authors.lastname: Piazza
authors.forename: P
authors.initials: P
authors.lastname: Pingue
authors.forename: A
authors.initials: A
authors.lastname: Tredicucci
authors.forename: F
authors.initials: F
authors.lastname: Beltram
authors.forename: H E
authors.initials: HE
authors.lastname: Beere
authors.forename: D A
authors.initials: DA
authors.lastname: Ritchie
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D054023:Lasers, Semiconductor; D008029:Lighting / Q000295:instrumentation*; D033401:Microscopy, Acoustic / Q000295:instrumentation*; D055069:Terahertz Imaging / Q000295:instrumentation*; D055053:Terahertz Radiation