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Polarization-Dependent Forces and Torques at Resonance in a Microfiber-Microcavity System
Jinsheng Lu1, Vincent Ginis1,2, Cheng-Wei Qiu3
1Harvard John A. Paulson School of Engineering and Applied Sciences, 9 Oxford Street, Cambridge, Massachusetts 02138, USA.
Physical Review Letters
|May 19, 2023
Summary
Spin-orbit interactions in evanescent fields create polarization-dependent lateral forces. Resonances in microfiber-microcavity systems reveal these forces are not solely dependent on light helicity, offering new optomechanical control.
Area of Science:
- Optics
- Quantum Mechanics
- Nanotechnology
Background:
- Spin-orbit interactions in evanescent fields are crucial for understanding light-matter interactions.
- Polarization-dependent lateral forces on particles arise from spin momentum transfer.
- The interplay between particle resonances, light helicity, and lateral forces remains an open research question.
Purpose of the Study:
- To investigate polarization-dependent phenomena in a microfiber-microcavity system with whispering-gallery-mode resonances.
- To understand how particle resonances synergize with incident light's helicity and lateral forces.
- To unify and intuitively understand polarization-dependent optical forces.
Main Methods:
- Utilizing a microfiber-microcavity system to host whispering-gallery-mode resonances.
- Analyzing the influence of light polarization and helicity on lateral forces at resonance.
- Developing a generalized theoretical framework for optical lateral forces.
Main Results:
- Lateral forces at resonance are not directly proportional to incident light helicity.
- Polarization-dependent coupling and resonance phases contribute additional helicity effects.
- Optical lateral forces exist even with zero incident light helicity.
Conclusions:
- Introduced a generalized law for optical lateral forces, unifying polarization-dependent phenomena.
- Demonstrated novel helicity contributions arising from resonance effects.
- Opened avenues for engineering polarization-controlled resonant optomechanical systems.
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