Figure 1
From: Polarization-selective four-wave mixing in a degenerate multi-level system
(a) Simplified schematic of coupling-probe spectroscopy. The laser beams are linearly polarized, and the probe beam passing through a polarizer with a polarization angle \(\alpha \) is detected. (b) Energy level diagram for the 85Rb D2 line. The red arrows represent excitation by the laser beams where the quantization axis is chosen as the propagation direction of the lasers. (c) Part of an energy level diagram with Zeeman magnetic sublevels. The excitations by the coupling and probe beams are denoted as c and p, respectively. (d) Simple diagram for the FWM signal generation.
