Abstract-High-resolution antenna near-field imaging and sub-THz measurements with a small atomic vapor-cell sensing element

David A. Anderson, Eric Paradis, Georg Raithel, Rachel E. Sapiro, Christopher L. Holloway

https://arxiv.org/abs/1804.09789

Atomic sensing and measurement of millimeter-wave (mmW) and THz electric fields using quantum-optical EIT spectroscopy of Rydberg states in atomic vapors has garnered significant interest in recent years towards the development of atomic electric-field standards and sensor technologies. Here we describe recent work employing small atomic vapor cell sensing elements for near-field imaging of the radiation pattern of a Ku-band horn antenna at 13.49 GHz. We image fields at a spatial resolution of λ/10 and measure over a 72 to 240 V/m field range using off-resonance AC-Stark shifts of a Rydberg resonance. The same atomic sensing element is used to measure sub-THz electric fields at 255 GHz, an increase in mmW-frequency by more than one order of magnitude. The sub-THz field is measured over a continuous ±100 MHz frequency band using a near-resonant mmW atomic transition.