Photorefractive tuning of whispering gallery modes of a spherical resonator integrated inside a microstructured optical fibreK. Kosma, I. Konidakis and S. PissadakisEur. Phys. J. Special Topics, 223 10 (2014) 2035-2040DOI: https://doi.org/10.1140/epjst/e2014-02246-3