Highly sensitive atomic based MW interferometry

Abstract

We theoretically study a scheme to develop an atomic based micro-wave (MW) interferometry using the Rydberg states in Rb. Unlike the traditional MW interferometry, this scheme is not based upon the electrical circuits, hence the sensitivity of the phase and the amplitude/strength of the MW field is not limited by the Nyquist thermal noise. Further, this system has great advantage due to its much higher frequency range in comparision to the electrical circuit, ranging from radio frequency (RF), MW to terahertz regime. In addition, this is two orders of magnitude more sensitive to field strength as compared to the prior demonstrations on the MW electrometry using the Rydberg atomic states. Further, previously studied atomic systems are only sensitive to the field strength but not to the phase and hence this scheme provides a great opportunity to characterize the MW completely including the propagation direction and the wavefront. The atomic based MW interferometry is based upon a six-level loopy ladder system involving the Rydberg states in which two sub-systems interfere constructively or destructively depending upon the phase between the MW electric fields closing the loop. This work opens up a new field i.e. atomic based MW interferometry replacing the conventional electrical circuit in much superior fashion.

Nature of interference between Autler-Townes peaks in multi-level system

“…The study of the loopy system is very important as it further authenticates our approach for the dressed states as in this case the interference terms, κ ′ s and Ω ′ p s can be complex. The various loopy system has been discussed previously [26][27][28][29].…”

Laser interferometry based on atomic coherence

“…EIT for chain or branching system does not depend upon the phase difference of the control and probe lasers but only the robustness of it depends upon their phase stability [12]. However in the loopy systems EIT depends upon the phase difference between probe and control lasers [13][14][15][16][17]. The loopy system provides two paths of excitation which interfere with each other constructively or destructively depending upon the phase difference between control and probe lasers.…”

Measurement of the Near Field Distribution of a Microwave Horn Using a Resonant Atomic Probe

“…The magnitude of the AT splitting, γ AT , is proportional to Ω MW , and so the magnitude of the splitting can be used to make an atom-based microwave field measurement. Rydberg EIT [10][11][12], a quantum coherence effect of the interaction between Rydberg atoms and lasers, will be employed to optically detect the microwave dressed AT splitting γ AT induced by the microwave field [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. Additionally, we can use this kind of resonant Rydberg transition and fluorescence to detect THz radiation [30,31].…”