title: Note: Near-field imaging of thermal radiation at low temperatures by passive millimeter-wave microscopy.
abstract: Imaging of thermal radiation with a spatial resolution below the diffraction limit is demonstrated with a passive millimeter-wave microscope. This technique utilizes a sensitive radiometric receiver in combination with a scanning near-field microscope. Experiments were performed at 50 GHz (λ = 6 mm) with sample temperatures ranging from room temperature down to 160 K, and the performance was shown to be superior to that achieved with passive imaging systems in the infrared region. The images are affected by non-uniformities in the transmission of thermal radiation from the sample to the receiver via the near-field probe and the reflection of thermal radiation back to the receiver from the probe. The effects of these non-uniformities were successfully removed using a sample image acquired by active measurements using a vector network analyzer.
authors.affiliation: Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan. nozokido@eng.u-toyama.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Nozokido
authors.forename: M
authors.initials: M
authors.lastname: Ishino
authors.forename: H
authors.initials: H
authors.lastname: Kudo
authors.forename: J
authors.initials: J
authors.lastname: Bae