We demonstrate light coupling from femtosecond laser written diamond waveguide operating at the telecommunication wavelengths to a silicon microsphere resonator. Type II waveguides are written on a diamond platform and Fabry-Pérot resonances are excited in the diamond waveguides by bare fiber coupling in and out of the waveguide. The Fabry-Pérot resonances have a free spectral range of 87 pm, and a maximum Q-factor of 3.9 × 104. The diamond waveguide is used to excite TM-polarized whispering gallery modes of the 1 mm silicon microsphere, since the type II waveguides support TM modes better as compared to TE modes. The whispering gallery mode spacing is measured as 0.257 nm and the highest Q-factor is 6.2 × 104. This evanescent coupling method to high Q-factor silicon microsphere resonances by femtosecond laser written diamond waveguides can be further used for filtering and sensing applications in various photonic lightwave circuits.

Femtosecond laser written diamond waveguide excitation of the whispering gallery modes in a silicon microsphere

Sotillo B.;Bharadwaj V.;Ramponi R.;Eaton S. M.
2019-01-01

Abstract

We demonstrate light coupling from femtosecond laser written diamond waveguide operating at the telecommunication wavelengths to a silicon microsphere resonator. Type II waveguides are written on a diamond platform and Fabry-Pérot resonances are excited in the diamond waveguides by bare fiber coupling in and out of the waveguide. The Fabry-Pérot resonances have a free spectral range of 87 pm, and a maximum Q-factor of 3.9 × 104. The diamond waveguide is used to excite TM-polarized whispering gallery modes of the 1 mm silicon microsphere, since the type II waveguides support TM modes better as compared to TE modes. The whispering gallery mode spacing is measured as 0.257 nm and the highest Q-factor is 6.2 × 104. This evanescent coupling method to high Q-factor silicon microsphere resonances by femtosecond laser written diamond waveguides can be further used for filtering and sensing applications in various photonic lightwave circuits.
2019
Diamond machining; Laser materials processing; Microcavities; Optical resonators; Resonance; Waveguides; Whispering gallery modes
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1132183
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