Simultaneous multiband radio-frequency detection using high-orbital-angular-momentum states in a Rydberg-atom receiver
Gianluca Allinson, Matthew J. Jamieson, Andrew R. MacKellar, Lucy A. Downes, Charles S. Adams, Kevin J. Weatherill
Abstract
We demonstrate simultaneous detection of radio-frequency (rf) fields ranging from the very high-frequency (VHF) band (128 MHz) to terahertz frequencies (0.61 THz) using high-orbital-angular-momentum (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>ℓ</a:mi></a:math>) states in a caesium Rydberg-atom receiver. rf fields are applied concurrently to a series of atomic transitions, where the application of each field allows access to the next-highest <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>ℓ</b:mi></b:math> state and the energy separations between states become progressively smaller, allowing access to a very wide range of radio frequencies. We show that the optical response of the system in the presence of the rf fields can be reproduced theoretically using a simple Lindblad-master-equation approach. Furthermore, we demonstrate experimentally that a series of amplitude-modulated tones can be detected simultaneously using a wide range of carrier frequencies. This demonstration opens the way for Rydberg receivers to access low-frequency rf bands at low principal quantum number and allows for communications across multiple bands simultaneously using a single optical receiver. Moreover, the experimental method presented allows for high-resolution spectroscopy of high-orbital-angular-momentum states in alkali-metal atoms. Published by the American Physical Society 2024