High-frequency self-induced oscillations in a silicon nanocavity

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Nonlinear Optics

Background:

• Silicon photonic crystal nanocavities are key components for integrated optics.
• Understanding nonlinear optical phenomena in these cavities is crucial for advanced applications.
• Achieving high-frequency, spectrally pure oscillations is a significant challenge in optical systems.

Purpose of the Study:

• To demonstrate self-induced gigahertz (GHz) oscillations in silicon photonic crystal nanocavities.
• To investigate the underlying mechanisms of self-pulsing, including nonlinear cavity response and photon lifetime.
• To develop a theoretical model for analyzing oscillation onset, amplitude, and frequency dependence on input power.

Main Methods:

• Optical pumping of a silicon photonic crystal nanocavity.
• Experimental observation and characterization of self-induced oscillations.
• Development and application of a theoretical model to analyze oscillation dynamics.

Main Results:

• Successfully generated self-induced oscillations at frequencies above 1 GHz with high spectral purity.
• Identified the interplay between nonlinear cavity response and photon cavity lifetime as the cause of self-pulsing.
• The theoretical model accurately predicts oscillation characteristics and their dependence on input power and frequency.

Conclusions:

• Silicon photonic crystal nanocavities can support high-frequency, spectrally pure self-induced oscillations.
• The developed model provides valuable insights into the physics of nonlinear optical phenomena in these cavities.
• Future theoretical work suggests the potential for achieving oscillations exceeding 50 GHz.