Spatial distribution measurement of the microwave electric field strength via the Autler-Townes effect of Rydberg atom

We demonstrate the high-resolution spatial feature measurement of microwave electric field using an cesium atomic vapor cell based on the electromagnetically induced transparency (EIT) spectrum of
¹³³
Cs Rydberg atom. The microwave electric field with the frequency of 6.95 GHz couples the transition of 47D5/2→48P3/2 Rydberg states. The EIT spectrum of a 6S1/2-6P3/2-47D5/2 ladder system will split by the Autler-Townes(AT) effect under the microwave electric field. The dependence of AT splitting separation on the microwave electric fields strength is observed. Moreover, we present the imaging of the spatial feature of microwave electric field in the atomic vapor cell. The theoretical maximum spatial resolution is about λMw/430.