Optically stimulated electron paramagnetic resonance: Simplicity, versatility, information content

V O Kozlov; A A Fomin; I I Ryzhov; G G Kozlov

doi:10.1016/j.jmr.2023.107427

Optically stimulated electron paramagnetic resonance: Simplicity, versatility, information content

J Magn Reson. 2023 Jun:351:107427. doi: 10.1016/j.jmr.2023.107427. Epub 2023 Apr 17.

Authors

V O Kozlov¹, A A Fomin¹, I I Ryzhov², G G Kozlov³

Affiliations

¹ Spin Optics Laboratory, Faculty of Physics, St Petersburg State University, Peterhof, Ul'yanovskaya ul., 1, Saint Petersburg 198504, Russia.
² Spin Optics Laboratory, Faculty of Physics, St Petersburg State University, Peterhof, Ul'yanovskaya ul., 1, Saint Petersburg 198504, Russia; Photonics Department, Faculty of Physics, St Petersburg State University, Peterhof, Ul'yanovskaya ul., 1, Saint Petersburg 198504, Russia.
³ Spin Optics Laboratory, Faculty of Physics, St Petersburg State University, Peterhof, Ul'yanovskaya ul., 1, Saint Petersburg 198504, Russia; Solid State Department, Faculty of Physics, St Petersburg State University, Peterhof, Ul'yanovskaya ul., 1, Saint Petersburg 198504, Russia. Electronic address: g.kozlov@spbu.ru.

PMID: 37087862
DOI: 10.1016/j.jmr.2023.107427

Abstract

A simple technique for observing optically stimulated electron paramagnetic resonance (OSEPR) is proposed and investigated. The versatility and information content of the described technique is demonstrated by the example of the OSEPR spectra of systems that are unpopular for this type of spectroscopy: a crystal with rare-earth ions Nd³⁺ and a doped semiconductor GaAs. In addition, the OSEPR spectrum of atomic cesium is presented, in which an optical nonlinearity is observed that makes it possible to estimate the Rabi frequency for the relevant optical transition. The effects observed in the described experiments (switching of peaks to dips, light-induced splitting of the OSEPR lines, and the appearance of a spectral feature at the double-Larmor frequency) are interpreted using the model proposed in the theoretical part of the work. The suggested interpretation shows the possibility of using the described OSEPR technique to estimate not only 'magnetic' parameters of the model Hamiltonian (g-factors, spin relaxation times), but also the Rabi frequencies characterizing optical transitions.

Keywords: Atomic vapour; Larmor frequency; Optically detected ESR; Rabi frequency; Rare-earth ions; Semiconductors.