Figure 5
From: Plane photoacoustic wave generation in liquid water using irradiation of terahertz pulses
Photoacoustic wave propagation induced by a single THz pulse. Snapshot images of (A) the photoacoustic wave induced by the THz-FEL with a frequency of 5 THz and at delay times of (B) 60, (C) 120, and (D) 180 ns. These images were taken with a time gate of 10 ns. A movie consisting of sequential snapshot images is shown in Supplementary Video S2 online. (E) Speed of the photoacoustic waves as functions of depth for different THz frequencies.
