Fig. 1: Time-resolved pump-probe spectroscopy.
From: Large scale purification in semiconductors using Rydberg excitons
a Normalized probe laser transmission spectrum of Rydberg excitons from n = 9 up to the band gap at 1.3 K. b Left axis: Differential transmission ΔI = I0 − I(pump) in a cw pump-probe experiment with npump = 16 and nprobe = 9. For low pump intensities the transmission is reduced (purification). For large pump intensities the transmission is enhanced (blockade). Right axis: Norm. transmission around the nprobe = 9 resonance for comparison. c Pump-intensity series of time resolved relative transmission in a pulsed pump-probe experiment for constant probe power. Purification and blockade may occur simultaneously, but are clearly distinguishable. τ1 decreases with pump power. The purple dashed lines indicate the duration of the pump pulse. d Breakdown of a typical relative transmission time trace for a pump intensity of 124 \(\frac{mW}{c{m}^{2}}\). Upon the arrival of the pump beam indicated by the dashed purple lines, blockade sets in immediately and vanishes immediately at the end of the pump beam. Purification slowly builds up during a time τ1 and decays on an even slower time τ2. Considering blockade and purification simultaneously reproduces the step-like structure of the measured relative transmission. e Same as b but for npump < nprobe, where only positive amplitudes are observed.
