Sensitivity Improvement and Determination of Rydberg Atom-Based Microwave Sensor

Abstract

We present a theoretical and experimental investigation of the improvement and determination of the sensitivity of Rydberg atom-based microwave RF sensor. An optical Bloch equation has been set up based on the configuration that two-color cascading lasers exciting atom to highly Rydberg state and a microwave RF coupling this Rydberg state to its adjacent neighbor. The numerical simulation shows that the sensitivity of the atomic RF sensor is correlated with the amplitude strengths of the applied two lasers and the RF itself. It also depends on the frequency detuning of the coupling laser, which induces an asymmetrically optical splitting. The coupling laser frequency fixing at the shoulder of the stronger one is more favorable for a higher sensitivity. Accordingly, we perform an experimental demonstration for the optimization of all these parameters and the sensitivity is improved to 12.50(04) nVcm−1·Hz−1/2.

Rydberg Atomic Sensor Sensitivity Optimization Using Detuned Microwave Field

“…Numerical simulations and experimental results show that the sensitivity of the Rydberg atomic sensor is related to the amplitude intensity of the two lasers and microwave electric. The microwave electric detection sensitivity can be improved to 12.5 nV•cm −1 Hz −1/2 by detuning the coupling laser frequency, which is the highest sensitivity achieved in experiments so far [5]. For applications in communication systems, predicting the Rydberg atomic sensor performance under different parameter settings through theoretical analysis and numerical simulation is significant.…”

“…Experimental techniques with ultrastable cavities can achieve extremely narrow linewidth laser beam and high power stabilization, which can increase the system sensitivity to the level higher than 100 nV•cm −1 Hz −1/2 . The optical readout noise is the dominant factor limiting the detection sensitivity [4], [5]. Except for apparatus performance improvement, new detection and readout techniques are the options left.…”

Sensitivity of Rydberg-atom receiver to frequency and amplitude modulation of microwaves

“…In recent years Rydberg-atom based microwave sensors have attracted attention of many researchers, owing to substantial sensitivity of Rydberg-to-Rydberg microwave (MW) transitions and straightforward measurement scheme. Atomic transitions have been proposed as easily reproducible electric field amplitude standard in the MW regime [1], and various realizations of MW modulation have led to enhanced detection sensitivity [2,3] (likewise did modulation of optical fields [4]), as well as to transmitting both analogue [5][6][7][8][9] and digital [10][11][12][13][14][15] information via Rydberg atomic receivers. There were also successful attempts at further characterizing measured MW field properties, such as frequency [16], phase [16][17][18][19], polarization [20,21], and angle-of-arrival [22].…”

Bright and dark Autler–Townes states in the atomic Rydberg multilevel spectroscopy

“…Today the multifrequency excitation of a multilevel system is a quite common experimental feature for different targets, and the Rydberg atomic states in ultracold samples offer a very interesting research area owing to their large dipole transition moments leading to very strong atomlaser interactions. We mention here the refined spectroscopic investigations, as the electromagnetic induced transparency in references [9][10][11][12], and the four-wave mixings and multiwave ones for the generation of radiation at new wavelengths [13,14].…”

“…However it requires a more elaborate description. The AT process, well characterised in atomic/molecular and solid state spectroscopy, has received recently a new interest within a different context: the precise determination of a microwave (mw) field amplitude for calibration purposes as in the Rydberg experiments by [10][11][12][16][17][18][19][20][21][22][23][24][25][26][27]. Mw radiation is applied to cold atoms in Rydberg states where owing to the very large electric dipole moment even a weak mw field produces a measurable AT splitting.…”