Laser Site-Selective Spectroscopy and Magnetic Hyperfine Splittings of Ho$^{3+}$ doped Y$_{2}$SiO$_{5}$

TL;DR

This study employs laser site-selective spectroscopy and high-resolution absorption to identify crystal-field energy levels and hyperfine structures of Ho$^{3+}$ ions in Y$_{2}$SiO$_{5}$, revealing magnetic field effects and avoided crossings.

Contribution

It provides detailed crystal-field energy levels and hyperfine structures of Ho$^{3+}$ in Y$_{2}$SiO$_{5}$, including magnetic field effects, which were previously uncharacterized.

Findings

51 crystal-field energy levels identified

Complex hyperfine patterns observed

Avoided crossings detected below 0.5 Tesla

Abstract

Laser site-selective spectroscopy and high-resolution absorption measurements have been used to determine 51 crystal-field energy levels for one of the Ho$^{3+}$ centres in Y$_{2}$SiO$_{5}$. This centre is denoted as Site 2 and has been tentatively assigned as the seven-fold coordinated centre. High resolution absorption measurements reveal complex hyperfine patterns that obey and approximate selection rule. The application of a magnetic field along the three optical axes reveals the presence of avoided crossings below 0.5 Tesla, in both the ground and excited states.