We demonstrate microscopic imaging of surface plasmon polaritons (SPPs) on silver films excited by 11 fs near-infrared laser pulses. A fluorescence layer placed on the silver film converts surface electromagnetic fields to propagating lights in visible wavelengths via two-photon excitation process. The wavelength of SPP determined from fluorescence micrographs agrees well with the calculated value of SPP at the silver-fluorescent film interface.

Nonmembers, Keisuke DOMAN † †b) , Yasutomo KAWANISHI † † †c) , Takatsugu HIRAYAMA † † † †d) , Members, Ichiro IDE † † †e) , Senior Member, Daisuke DEGUCHI † † † † †f) , Member, and Hiroshi MURASE † † †g) , Fellow SUMMARY We introduce a method to estimate the attractiveness of a food photo. It extracts image features focusing on the appearances of 1) the entire food, and 2) the main ingredients. To estimate the attractiveness of an arbitrary food photo, these features are integrated in a regression scheme. We also constructed and released a food image dataset composed of images of ten food categories taken from 36 angles and accompanied with attractiveness values. Evaluation results showed the effectiveness of integrating the two kinds of image features.

No abstract

No abstract

We demonstrate imaging of surface plasmon polaritons (SPPs) on a silver film using a two-photon fluorescence microscopy technique. Surface plasmon waves launched from an edge of a silver film under a light irradiation of 11-fs near-infrared laser pulses promote formation of intensity beats in nearfi elds through SPP-light interference. Dye molecules embedded in a thin PMMA layer on a silver fi lm up-convert the near-infrared surface fi elds to propagating lights in visible range through a two-photon excitation, which enables to image the near-fi elds with using a conventional optical microscope. The wavelength of SPP determined from the beat wavelength of near-fi elds agrees well with an evaluation using dielectric properties of sample materials and the dispersion relation of SPP.