Fig. 1: Overview of key setup components, features and principles.
From: Broadband transient full-Stokes luminescence spectroscopy
a, Schematic of the key optical components and measurement procedure. Excitation by a pulsed laser (200 fs, variable repetition rate 0.5–50 kHz) in the 90° geometry eliminates certain polarization artefacts, whereas the 180° geometry is more suitable for thin samples. Superachromatic waveplates (HWP for half-wave plate, QWP for quarter-wave plate) in appropriate orientations transform polarization components into orthogonal linear components, which are separated by a Wollaston prism and passed through a grating spectrograph. Orthogonally polarized spectra are recorded simultaneously as two tracks on a single CCD array detector. An intensifier tube is electronically gated to provide time resolution. Waveplate rotation, automatable by motorized housings, allows swapping the detection tracks, which results in the cancellation of the largest channel transmission mismatches and temporal instabilities. b, Calculated intensities at vertical and horizontal detection tracks as a function of QWP angle for an RCP luminescence input and HWP angle for a linearly polarized input. Two tracks are simultaneously recorded, and the measurement is repeated at a second QWP/HWP position at which the tracks swap. c, Calculated intensity difference between measurement tracks as a function of both QWP and HWP angle for the pure Stokes basis polarizations. Red crosses indicate angles where measurements are taken for that polarization component. For reference, black crosses (each of which is at ΔI = 0) indicate angles where measurements are taken for other polarization components.
