Low-loss and high-resolution mechanical mode tuning in microspheres

Area of Science:

• Optomechanics
• Mechanical Resonators
• Nanophotonics

Background:

• Optomechanical systems offer significant potential but are limited by a lack of tunability.
• Mechanical frequency tuning in these systems remains an under-researched area.
• Precise control over mechanical frequencies is crucial for scalable optomechanical applications.

Purpose of the Study:

• To develop an ultra-fine, low-loss method for dynamical mechanical frequency tuning in microspheres.
• To investigate the feasibility of achieving arbitrary-function mechanical resonance tuning.
• To evaluate the impact of geometric deformation on tuning resolution and mechanical quality factor.

Main Methods:

• Achieved frequency tuning by applying axial compression to a microsphere.
• Evaluated tuning resolution, mechanical quality factor (Qm) variation, and geometric deformation effects.
• Utilized sine function modulation for arbitrary-function mechanical resonance tuning, validated by Pearson coefficient analysis.

Main Results:

• Demonstrated ultra-fine, low-loss dynamical mechanical frequency tuning with a resolution of approximately 4% of the mechanical linewidth.
• Maintained the mechanical quality factor (Qm) within 2.9% of its untouched value during tuning.
• Achieved arbitrary-function mechanical resonance tuning with a Pearson coefficient exceeding 99.3%.

Conclusions:

• Axial compression of microspheres provides an effective method for ultra-fine mechanical frequency tuning.
• The developed technique offers high precision and minimal impact on the mechanical quality factor.
• This advancement enables scalable optomechanical applications, including mechanical vibration synchronization and optomechanics-based optical wavelength conversion.