Optical Spectroscopy of Waveguide coupled Er${}^{3+}$ ensembles in CaWO${}_4$ and YVO${}_4$

Fabian Becker, Anna Selzer, Lorenz J. J. Sauerzopf +4

We present an optical study of near-surface Er${}^{3+}$ ensembles in waveguide-integrated CaWO${}_4$ and YVO${}_4$, investigating how nanophotonic coupling modifies rare-earth spectrosco…