Optical Frequency Conversion in Silica-Whispering-Gallery-Mode Microspherical Resonators

Abstract

High quality factor whispering-gallery-mode microresonators are ideally suited for nonlinear optical interactions. We analyze, experimentally and theoretically, a variety of χ((3)) nonlinear interactions in silica microspheres, consisting of third harmonic generation and Raman assisted third order sum-frequency generation in the visible. A tunable, room temperature, cw multicolor emission in silica microspherical whispering-gallery-mode microresonators has been achieved by controlling the cavity mode dispersion and exciting nonequatorial modes for efficient frequency conversion.

Nonlinear and Quantum Optics with Whispering Gallery Resonators

“…Along with the third harmonic, series of discrete blueshifted emission peaks arising from FWM of the input radiation and the stimulated Raman-scattered radiation were reported [144,453]. A similar phenomenon was observed in a large, 7 mm in diameter, crystalline MgF 2 resonator [381], in addition to the hyper-parametric comb and stimulated Raman scattering.…”

“…Recently, efficient THG was demonstrated in silica micro toroids [159], Si 3 N 4 micro rings [356], and in silica micro spheres [453]. All these resonators were pumped in a low-power CW regime at 1550-1560 nm wavelength, producing visible (green) third harmonic.…”

Kerr nonlinear switching in a hybrid silica-silicon microspherical resonator

“…Of these fiber resonators, much focus has been placed on devices that are fashioned from the extremely low loss silica platforms so that Q factors above 10 7 can be readily achieved [7,9]. Thus, despite silica's relatively modest nonlinear coefficients, these ultra-high-Q resonators have still found use for nonlinear applications including all-optical switching [10,11] and third harmonic generation [12].…”

Multicolour emission in silica whispering gallery mode microspherical resonators

“…Tuning the THG signal is also possible by varying the pump wavelength in the range of the EDFA band and selecting the proper microsphere diameters [25].…”