This research was funded by the US Department of Energy Basic Science Office under Contract No. DE-FG02- 10ER46406.
Physical Review B
Multiphoton processes, Multiphoton excitation microscopy, Near-field microscopy
We report the observation of optical near fields in a photonic waveguide of conductive indium tin oxide (ITO) using multiphoton photoemission electron microscopy (PEEM). Nonlinear two-photon photoelectron emission is enhanced at field maxima created by interference between incident 410-nm and coherently excited guided photonic waves, providing strong phase contrast. Guided modes are observed under both transverse magnetic field (TM) and transverse electric field (TE) polarized illuminations and are consistent with classical electromagnetic theory. Implications on the role of multiphoton PEEM in optical near-field imaging are discussed.
Fitzgerald, J. P. S., et al. "Photonic near-field imaging in multiphoton photoemission electron microscopy." Physical Review B 87.20 (2013): 205419.