Resonance shift induced by free carriers of a silicon resonator of quadrangular shape

Abstract

The nonlinear optical interaction of a silicon resonator with a quadrangular shaped smooth bend is studied with inclusion of free carriers (FCs), two-photon absorption, the Kerr effect, and loss. It is shown that for the range of input light power from zero up to 2 W, the incident light transmits between the silicon resonator and waveguide linearly. However, with an increase of light power from 2 W to higher values, the light transmission decreases very rapidly, so that it approximately vanishes at about 10 W. Furthermore, the resonance spectrum and stability condition of the silicon resonator in the nonlinear regime is studied with inclusion of FC dispersion and FC absorption for continuous wave operation. Thermal effects induced by FC absorption increase the refractive index, which causes a redshift of about 1.2 nm for 125.13 mW light power.

Keywords:

• silicon resonator
• two-photon absorption
• free carrier
• resonance shift

Acknowledgements

We greatly appreciate fruitful discussions with Professor Andrea Melloni, Carlo Ferrari and Francesco Morichetti.