Electromagnetically Induced Transparency (EIT) and Autler-Townes (AT) splitting in the presence of band-limited white Gaussian noise

Abstract

We investigate the effect of band-limited white Gaussian noise (BLWGN) on electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting, when performing atom-based continuous-wave (CW) radio-frequency (RF) electric (E) field strength measurements with Rydberg atoms in an atomic vapor. This EIT/AT-based E-field measurement approach is currently being investigated by several groups around the world as a means to develop a new SI traceable RF Efield measurement technique. For this to be a useful technique, it is important to understand the influence of BLWGN. We perform EIT/AT based E-field experiments with BLWGN centered on the RF transition frequency and for the BLWGN blue-shifted and red-shifted relative to the RF transition frequency. The EIT signal can be severely distorted for certain noise conditions (bandwidth, center-frequency, and noise power), hence altering the ability to accurately measure a CW RF E-field strength. We present a model to predict the changes in the EIT signal in the presence of noise. This model includes AC Stark shifts and on resonance transitions associated with the noise source. The results of this model are compared to the experimental data and we find very good agreement between the two.

Detecting and Receiving Phase-Modulated Signals With a Rydberg Atom-Based Receiver

“…Furthermore, there are indications that this Rydberg atom-based system may be less susceptible to noise. As was the case in measuring CW electric-field strengths 19 , where we performed experiments measuring CW E-field strengths using this atom-based approach in the presence of band-limited white Gaussian noise and we showed that the E-field strength could be detected in low CW-signal to noise-power ratio conditions. The detection scheme discussed here can be improved by reducing laser noise and systematic effects, which is the topic of future work.…”

Embedding a Rydberg Atom-Based Sensor Into an Antenna for Phase and Amplitude Detection of Radio-Frequency Fields and Modulated Signals

“…The atom-based receiver interacts with noise in a different manner than conventional systems and as such may be less susceptible to noise. This is indicated in [24], [27], where E-field strengths and modulated signals could be measured and detected in the presence of band-limited white Gaussian noise for low CW-signal to noise-power ratio conditions. While the bandwidth of these Rydberg-atom receivers/sensors depend on the Rydberg state chosen, in general, the bandwidth is limited by the response time of the atomic transition, which is on the order of 10 MHz [29], [39], and [40].…”

“…However, we can make a few preliminary observations concerning some of the aspects of Rydberg atom-based systems. Rydberg atom-based receivers and sensors have potential advantages over conventional radio technologies, which include: (1) micron-size sensors over a frequency range of 500 MHz to 1 THz [6], [7], (2) multiband (or mutli-channel) operation in one compact vapor cell [27], [38], (3) the possibility of being less susceptible to noise [24] and [27], (4) ultra-high sensitivity reception from 500 MHz to 1 THz [28] with sub Hz frequency resolution, and (5) no need for traditional down-conversion electronics because the atoms automatically down-convert the phase modulated signals to an IF. Furthermore, the Rydberg atom-based receiver has the possibility of being less affected by ''spoofing'' and ''jamming'' (as well as noise) when compared to conventional systems.…”

“…The idea of developing a fundamentally new method for measuring RF E-fields with Rydberg atoms started about eight years ago when two groups (one led by the University of Oklahoma and one led by the National Institute of Standards and Technology) launched sizable efforts to investigate the feasibility of using Rydberg atoms for SI-traceable E-field strength measurements [4], [5], and [6]. Since this time, much progress has been made in the use of Rydberg atombased E-field sensors by various groups [7]- [24]. Most of this work concentrated on the amplitude (both weak and strong field strengths) and polarization.…”

A Multiple-Band Rydberg Atom-Based Receiver: AM/FM Stereo Reception

“…We (and others) have made significant progress in the development of new radio frequency (RF) electric (E) field strength and power metrology techniques based on the large dipole moments associated with Rydberg states of alkali atomic vapor [either cesium ( 133 Cs) or rubidium ( 85 Rb)] placed in glass cells [2]- [20]. In this approach, we use the phenomena of electromagnetically induced transparency (EIT) for the E-field sensing.…”