Figure 1: Experimental setup.
From: Coherent and dynamic beam splitting based on light storage in cold atoms
(a) Conceptual schematic of the Mach-Zehnder interferometer utilizing the beam splitter based on EIT light storage in a cold atom ensemble. (b) The input signal is resonant with |g〉-|e〉. Two control lasers are applied between |s〉-|e〉: on resonant for the forward control (ωFWC) and with a detuning Δ for the backward control (ωBWC). The input signal is then split into the two output beams: forward output (ωFWO, resonant to |g〉-|e〉) and backward output (ωBWO, with a detuning Δ to |g〉-|e〉). All fields are σ+ polarized. (c) The weak signal pulse is launched into an 87Rb MOT when the strong forward (FW) control beam is turned on. The angle between the FW control and the signal is 0.3°. Storage of the signal is achieved simply by turning off the FW control. After a certain storage time, the input signal can be retrieved into the forward (FW) or backward (BW) outputs by turning on the FW or BW controls, respectively. AOM: acousto-optic modulator. BS: non-polarizing beamsplitter. PBS: polarizing beamsplitter. QWP: quarter wave plate. SMF: single-mode fiber. APD: avalanche photodiode.
