  In this work, we demonstrate a microwave magnetic field imaging technique
based on Rabi resonance with a cesium atom vapor cell. Rabi resonance signals
are generated when atoms interact with a phase-modulated microwave (MW) field
and are detected by a photodiode and camera. A low noise, high quantum
efficiency camera is used to capture a series of frames for different phase
modulation frequencies. Rabi frequencies of each spatial point in the field can
be measured by scanning the frames. Thus, the strength of the MW magnetic field
distribution is obtained by combing the Rabi frequencies, measured with camera
pixels in the range of the probe laser beam. The simple architecture of this
imaging setup holds great potential for the construction of compact/miniature
MW field sensors for material testing, field imaging of MW components, and
biomedical imaging.
