Engineering dissipation with phononic spectral hole burning.

Area of Science:

• Optomechanics
• Nano-electromechanics
• Integrated photonics
• Phononic device physics

Background:

• Silica devices support ultra-long-lived optical excitations but not acoustic phonons at low temperatures.
• Acoustic phonon dissipation in silica limits its use in phononic devices.
• Crystalline solids achieve long-lived acoustic phonons at cryogenic temperatures.

Purpose of the Study:

• To overcome acoustic phonon dissipation in silica at low temperatures.
• To enable long-lived phonon excitations in silica for novel phononic devices.
• To demonstrate engineerable phonon dynamics in glasses.

Main Methods:

• Nonlinear saturation using continuous drive fields of disparate frequencies.
• Phononic spectral hole burning.
• Development of a simple model for phononic saturation effects.

Main Results:

• Phonon dissipation reduced by over 90% in silica.
• Achieved wideband transparency window using optically generated phonon fields.
• Demonstrated steady-state phononic spectral hole burning.

Conclusions:

• Nonlinear saturation effectively reduces phonon dissipation in silica.
• Glasses can be utilized as low-loss phononic media.
• This work is a step towards engineerable phonon dynamics on demand.