54
3 Rotatable-Polarisation Terahertz Time-Domain Spectroscopy of Anisotropic Media
Fig. 3.6 Schematic diagram of the experiment comparing a projection of the THz polarisation
state by a WGP and b rotation of the polarisation state using a rotatable emitter. c Ellipticity and d
orientation angle of THz pulses after transmission through a WGP acting on the incident pulse at an
angle of 45 ◦ (blue lines), and without transmission through the WGP after the incident polarization
state has been rotated 45 ◦ by rotating the emitter (red lines). Shaded regions show the standard
deviation after 20 repeated scans. The dashed line in d represents the direction perpendicular to the
wires of the WGP
wires and determining the angle at which the transmitted THz amplitude |E| was a
maximum. The emitter was then rotated by 45
◦ such that the THz pulse incident on
the WGP would have equal components parallel and perpendicular to the wires. This
simulates the action of projecting a linear THz pulse at an angle of 45
◦ using a WGP.
The frequency-dependent ellipticity and orientation angle of the projected pulse are
shown by the blue lines in Fig. 3.6c, d, respectively. The WGP produces a highly
3 Rotatable-Polarisation Terahertz Time-Domain Spectroscopy of Anisotropic Media
Fig. 3.6 Schematic diagram of the experiment comparing a projection of the THz polarisation
state by a WGP and b rotation of the polarisation state using a rotatable emitter. c Ellipticity and d
orientation angle of THz pulses after transmission through a WGP acting on the incident pulse at an
angle of 45 ◦ (blue lines), and without transmission through the WGP after the incident polarization
state has been rotated 45 ◦ by rotating the emitter (red lines). Shaded regions show the standard
deviation after 20 repeated scans. The dashed line in d represents the direction perpendicular to the
wires of the WGP
wires and determining the angle at which the transmitted THz amplitude |E| was a
maximum. The emitter was then rotated by 45
◦ such that the THz pulse incident on
the WGP would have equal components parallel and perpendicular to the wires. This
simulates the action of projecting a linear THz pulse at an angle of 45
◦ using a WGP.
The frequency-dependent ellipticity and orientation angle of the projected pulse are
shown by the blue lines in Fig. 3.6c, d, respectively. The WGP produces a highly