Thermal image encryption obtained with a SiO2 space-variant subwavelength grating supporting surface phonon-polaritons Academic Article uri icon


  • Space-variant partially polarized thermal emission is investigated. We show that by coupling surface phonon-polaritons to a propagating field, large anisotropy of the emissivity is obtained within a narrow spectral range. We experimentally demonstrate this effect by fabricating a space-variant subwavelength grating on a SiO_2 substrate to encrypt an image in the polarization state of a thermal radiation field.

publication date

  • January 1, 2005