Fiber-Based Whispering Gallery Mode Microresonators for Optical Frequency Comb Generation in Telecommunication Range: Experiment and Numerical Simulation

Optical frequency combs including microresonator-based ones can be used in telecommunications as multi-carrier sources in wavelength-division multiplexing. We produced samples of silica fiber-based spherical microresonators potentially interesting for this application. Whispering gallery modes were excited by broadband spontaneous emission radiation of an Er:fiber laser source. Q-factors were estimated. We also investigated theoretically the possibility of using silica-based Ge $\mathrm {O}_{2}-$ doped glass microspheres for comb generation in the dissipative soliton regime pumped at 1550 nm. It was shown numerically that optical frequency combs with a spectral width from E-band to L-band can be obtained for microspheres doped with 20 mol.% $\mathrm {G}\mathrm {e}\mathrm {O}_{2}$.