Analysis of thermo-optic effect-based refractive index dynamic modulation in microspherical resonator

Area of Science:

• Optics
• Materials Science
• Nanotechnology

Background:

• The thermo-optic effect dynamically modulates refractive index in whispering gallery mode resonators.
• Low-frequency modulation offers large tuning ranges for mode locking, while high-frequency modulation is used for optical switching with limited tuning.
• Understanding dynamic temperature responses is crucial for advanced microresonator control.

Purpose of the Study:

• To theoretically introduce response functions describing dynamic temperature changes in microresonator mode volume and body.
• To experimentally verify the theoretical models in silica microspherical resonators.
• To investigate the dependence of the tuning range on modulation frequency.

Main Methods:

• Theoretical modeling of thermo-optic response functions.
• Experimental verification using silica microspherical resonators.
• Analysis of tuning range versus modulation frequency.

Main Results:

• Developed theoretical response functions for dynamic temperature changes.
• Experimentally validated the models in silica microspheres.
• Demonstrated a clear dependence of the tuning range on modulation frequency.

Conclusions:

• The study provides a theoretical framework and experimental validation for dynamic refractive index control in microresonators.
• The findings highlight the relationship between tuning range and modulation frequency.
• This research advances practical control of refractive index in microresonator devices.