Photonic bound states in the continuum governed by heating

Area of Science:

• Photonics
• Condensed Matter Physics
• Optical Engineering

Background:

• Photonic crystal microcavities offer unique light confinement properties.
• Liquid crystals provide tunable optical characteristics.
• Optical bound states in the continuum (BICs) exhibit sharp resonant features.

Purpose of the Study:

• To implement a photonic crystal microcavity with a heating-tunable liquid crystal resonant layer.
• To investigate the optical bound states in the continuum (BICs) within this tunable microcavity.
• To explore the potential of the microcavity's resonant properties for temperature sensing applications.

Main Methods:

• Fabrication of a photonic crystal microcavity incorporating a liquid crystal layer.
• Thermal tuning of the liquid crystal's refractive index via controlled heating.
• Optical spectroscopy to observe resonant lines and linewidth variations.

Main Results:

• Successful implementation of a liquid crystal tunable photonic crystal microcavity.
• Observation of multiple vanishing resonant lines corresponding to optical bound states in the continuum (BICs).
• Demonstration of abrupt changes in resonant linewidth near the BIC vanishing points.

Conclusions:

• The tunable photonic crystal microcavity effectively exhibits optical bound states in the continuum.
• The sensitivity of resonant linewidth to temperature variations makes it a viable sensing mechanism.
• This system presents a novel approach for high-resolution temperature sensing using photonic devices.