Sub-wavelength imaging and field mapping via electromagnetically induced transparency and Autler-Townes splitting in Rydberg atoms

Abstract

We present a technique for measuring radio-frequency (RF) electric field strengths with subwavelength resolution. We use Rydberg states of rubidium atoms to probe the RF field. The RF field causes an energy splitting of the Rydberg states via the Autler-Townes effect, and we detect the splitting via electromagnetically induced transparency (EIT). We use this technique to measure the electric field distribution inside a glass cylinder with applied RF fields at 17.04 GHz and 104.77 GHz. We achieve a spatial resolution of ≈100 µm, limited by the widths of the laser beams utilized for the EIT spectroscopy. We numerically simulate the fields in the glass cylinder and find good agreement with the measured fields. Our results suggest that this technique could be applied to image fields on a small spatial scale over a large range of frequencies, up into the sub-THz regime.

Continuous-frequency measurements of high-intensity microwave electric fields with atomic vapor cells

“…Weak microwave fields become detectable in Rydberg-atom-based EIT measurement via microwave-induced distortion and Autler-Townes splitting of EIT lines [2][3][4] . In this weakfield regime, microwave fields that are more than tens of MHz off-resonance from a Rydberg transition become hard detect, because AC level shifts decrease with increasing detuning.…”

“…Significant progress has been made in atom-based measurements of microwave electric fields using electromagnetically induced transparency in room-temperature alkali metal vapors, in which a laser beam addresses highly field-sensitive atomic Rydberg states [1][2][3] . The Rydberg-atom-based measurement approach has garnered broad interest at national metrology institutes for the establishment of new atomic measurement standards of microwave and millimeter-wave electric fields 4 , and holds promise for the development of atomic microwave electric-field sensors and measurement technologies with unprecedented bandwidth and dynamic range.…”

A high repetition rate experimental setup for quantum non-linear optics with cold Rydberg atoms

“…Consequently, the modified optical response of a Rydberg EIT medium [23] also provides a powerful tool to probe and image both DC electric [24][25][26][27] and microwave fields [28][29][30][31][32]. The application of external fields can also be used to enhance the effective photon interactions by introducing resonant dipole interactions: microwaves can directly couple to adjacent Rydberg states [13,33], while the Stark shift resulting from a DC electric field can tune the interactions at a Förster resonance [34].…”

Imaging electric fields in the vicinity of cryogenic surfaces using Rydberg atoms

“…Although detrimental effects of electric stray fields might be mitigated in some cases, e.g., by microwave frequency dressing [26], coating the surfaces with adsorbates [27] or choosing chemically inert atoms (such as helium) [28,29], techniques to measure stray fields are essential. A possible technique in this context is based on Rydberg-electromagnetically-induced transparency, with which also the microwave field in a glass cell [30] or of a coplanar waveguide (CPW) [31,32] has been characterized.In this article, we present a technique to measure static and time-dependent (microwave) electric fields above patterned surfaces in a cryogenic environment based on coherent Rydberg-Stark spectroscopy. We use a fast (v ≈ 1700 m/s) supersonic beam of metastable 1s 1 2s 1 1 S 0 * Electronic address: tthiele@phys.ethz.ch helium atoms.…”

“…Although detrimental effects of electric stray fields might be mitigated in some cases, e.g., by microwave frequency dressing [26], coating the surfaces with adsorbates [27] or choosing chemically inert atoms (such as helium) [28,29], techniques to measure stray fields are essential. A possible technique in this context is based on Rydberg-electromagnetically-induced transparency, with which also the microwave field in a glass cell [30] or of a coplanar waveguide (CPW) [31,32] has been characterized.…”