Cavity Optomechanics with Anderson-Localized Optical Modes.

Area of Science:

• Optics
• Condensed Matter Physics
• Nanotechnology

Background:

• Cavity optomechanics enhances light-matter interactions, enabling phenomena like optomechanically induced transparency.
• Previous studies overlooked the role of structural disorder in optomechanical systems.
• Disorder, typically analyzed using statistical physics, has not been explored in conjunction with optomechanics.

Purpose of the Study:

• To investigate the impact of structural disorder on light confinement and optomechanical interactions in photonic crystal waveguides.
• To explore Anderson localization of light induced by sidewall roughness in air-slot photonic crystal waveguides.
• To study the optomechanical coupling between disorder-induced optical modes and mechanical modes.

Main Methods:

• Fabrication of air-slot photonic crystal waveguides with controlled sidewall roughness.
• Characterization of optical modes using high-quality factors and sub-diffraction-limit mode volumes.
• Measurement of optomechanical coupling rates and observation of optomechanical backaction.

Main Results:

• Demonstration of Anderson-localized optical modes with quality factors up to 500,000 due to sidewall roughness.
• Observation of strong optomechanical coupling rates exceeding 200 kHz.
• Induction of mechanical amplification up to self-sustained oscillations via optomechanical backaction.

Conclusions:

• Sidewall roughness in photonic crystals can induce Anderson localization, creating novel optical modes.
• The interplay between disorder and optomechanics opens new avenues for exploring complex coupled systems.
• This work pioneers the study of optomechanics in the multiple-scattering regime.