[16a-WL1_201-1~11] 3.1 Basic optics and frontier of optics

9:15 AM - 9:30 AM JST(12:15 AM - 12:30 AM UTC)

[16a-WL1_201-2] Time-resolved observation of propagation-invariant space-time surface plasmon polariton

Kei Motoi¹, Gentaro Takeuchi¹, Kotaro Kihara¹, Naoki Ichiji², 〇Atsushi Kubo¹ (1.Univ. of Tsukuba, 2.The Univ. of Tokyo)

Keywords:

surface plasmon,structured light,femtosecond

Propagation-invariant space-time surface plasmon polaritons (ST-SPPs) were generated on a silver surface using space-time (ST) wave packets, a form of structured light, and were investigated by time-resolved measurements. ST wave packets synthesized from 10 fs laser pulses produced ST-SPPs with a characteristic X-shaped spatial intensity distribution. Two-photon fluorescence imaging was used to evaluate the group velocity and non-diffracting behavior. A group velocity of approximately 0.78c (c: the speed of light) and non-diffracting propagation over distances exceeding 90 µm were thereby demonstrated.