Applied Physics B

, Volume 100, Issue 4, pp 847–850

Thermo-optical tuning of whispering gallery modes in Er:Yb co-doped phosphate glass microspheres


DOI: 10.1007/s00340-010-4153-0

Cite this article as:
Ward, J.M. & Chormaic, S.N. Appl. Phys. B (2010) 100: 847. doi:10.1007/s00340-010-4153-0


We demonstrate an all-optical, thermally assisted technique for broad-range tuning of whispering gallery modes in microsphere resonators fabricated from an Er:Yb co-doped phosphate glass (IOG-2). The microspheres are pumped at 978 nm and the heat generated by absorption of the pump expands the cavity, thereby altering the cavity size and refractive index. We demonstrate a significant nonlinear tuning range of greater than 700 GHz of both C- and L-band cavity emissions via pumping through a tapered optical fibre. Finally, we show that large linear tuning up to ∼488 GHz is achievable if the microsphere is alternatively heated by coupling laser light into its support stem.

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Department of Applied Physics and InstrumentationCork Institute of TechnologyBishopstownIreland
  2. 2.Photonics CentreTyndall National InstituteLee MaltingsIreland
  3. 3.Physics DepartmentUniversity College CorkCorkIreland