Narrow-linewidth Fano microcavities with resonant subwavelength grating mirror.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Optical microcavities are crucial for various photonic applications.
• Fano resonance in optical systems offers unique spectral properties.
• High-quality factor resonators are essential for sensitive measurements.

Purpose of the Study:

• To theoretically and experimentally investigate optical microcavities with Fano resonance.
• To explore the relationship between microcavity length and spectral linewidth.
• To assess the potential of these microcavities for optomechanics and sensing.

Main Methods:

• Fabrication of plane-plane optical microcavities.
• Integration of broadband high-reflectivity mirrors with suspended 1D grating mirrors.
• Experimental characterization of spectral linewidths across varying cavity lengths (millimeter to few microns).
• Theoretical modeling of Fano resonance in microcavities.

Main Results:

• Observed reduction in spectral linewidth at shorter microcavity lengths.
• Demonstrated narrower linewidths compared to conventional broadband mirror cavities.
• Achieved high-quality factor Fano resonance in the microcavity design.
• Confirmed theoretical predictions for Fano cavity behavior.

Conclusions:

• The developed Fano microcavities exhibit narrow spectral linewidths and small mode volumes.
• High-mechanical quality ultrathin mirrors contribute to enhanced performance.
• These microcavities are promising for applications in optomechanics and sensing.