Fig. 1. Schematic of the tilted slit-groove interferometer: (a)top view,(b)excitation scheme.
Melentiev and his colleagues have realized a plasmonic interferometer formed by a nanoslit and a nanogroove in a single-crystal gold film. The possibility of measuring laser pulses of ultimately short durations, corresponding to two periods of a light wave (6 fs pulse duration), has been demonstrated using this interferometer.
Melentiev et al.,Femtosecond plasmon interferometer, Optics Communications, Volume 382, 2017, Pages 509-513.