Unidirectional emission and nanoparticle detection in a deformed circular square resonator

Area of Science:

• Optics and Photonics
• Nanotechnology
• Quantum Physics

Background:

• Microcavities are crucial for controlling light-matter interactions.
• Chirality in optical modes enables directional light emission.
• Sensing applications require high sensitivity to small particles.

Purpose of the Study:

• To introduce a novel deformed square resonator with asymmetric sides.
• To achieve strong optical chirality and unidirectional emission.
• To demonstrate nanoparticle detection using the cavity's unique optical properties.

Main Methods:

• Fabrication of a deformed square microcavity with asymmetric circular sides.
• Analysis of photon leakage through the interplay of stable islands and unstable manifolds in phase space.
• Investigation of optical mode chirality and far-field emission patterns.
• Monitoring changes in emission patterns upon nanoparticle binding.

Main Results:

• Achieved optical modes with chirality approaching 1 and simultaneous unidirectional emission by breaking mirror symmetry.
• Observed drastic changes in far-field emission patterns upon nanoparticle binding.
• Demonstrated the potential for chirality-based far-field detection of ultra-small nanoparticles.

Conclusions:

• The deformed microcavity offers a new platform for generating chiral light.
• The cavity's sensitivity to nanoparticle binding enables advanced sensing capabilities.
• This technology holds promise for the detection of nanoscale objects.