When particles are held in optical tweezers, we assume that they are in thermal equilibrium, in which the equipartition of energy determines the position variance of optically trapped spheres. Here we show that this condition only holds for very high symmetry cases, e.g. perfectly isotropic particles in unaberrated, linearly polarized Gaussian traps. We report an experimental observation that when a birefringent microsphere is held in a linearly polarised Gaussian optical trap in vacuum, spontaneous oscillations emerge that grow rapidly in amplitude and become increasingly coherent as the air pressure is reduced. Furthermore, when parametrically driven, these self-sustained oscillators exhibit an ultrahigh mechanical quality factor > 2 x 108, which can be highly sensitive to external purtabations.
|Title of host publication||Optical Manipulation and Structured Materials Conference 2020|
|Editors||Takashige Omatsu, Kishan Dholakia, Hajime Ishihara, Keiji Sasaki|
|Publication status||Published - 2020|
|Event||Optical Manipulation and Structured Materials Conference 2020 - Yokohama, Japan|
Duration: 2020 Apr 20 → 2020 Apr 24
|Name||Proceedings of SPIE - The International Society for Optical Engineering|
|Conference||Optical Manipulation and Structured Materials Conference 2020|
|Period||20/4/20 → 20/4/24|
Bibliographical noteFunding Information:
We acknowledge the support from Engineering and Physical Sciences Research Council (EP/030017/1) and Czech Science Agency (GA19-17765S).
© 2020 SPIE.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering