Precise in situ radius measurement of individual optically trapped microspheres using negative optical torque exerted by focused vortex beams
Fuente:
arXiv
Gespeichert in:
| Hauptverfasser: | , , , , , , , , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2023
|
| Schlagworte: | |
| Online-Zugang: | |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866914926087372800 |
|---|---|
| author | Diniz, Kainã Schoger, Tanja Moura, Guilherme T. Fonseca, Arthur L. Ether Jr, Diney S. Dutra, Rafael S. Ingold, Gert-Ludwig Viana, Nathan B. Neto, Paulo A. Maia |
| author_facet | Diniz, Kainã Schoger, Tanja Moura, Guilherme T. Fonseca, Arthur L. Ether Jr, Diney S. Dutra, Rafael S. Ingold, Gert-Ludwig Viana, Nathan B. Neto, Paulo A. Maia |
| contents | We demonstrate a new method for determining the radius of micron-sized particles trapped by a vortex laser beam. The technique is based on measuring the rotation experienced by the center of mass of a microsphere that is laterally displaced by a Stokes drag force to an off-axis equilibrium position. The rotation results from an optical torque pointing along the direction opposite to the vortex beam angular momentum. We fit the rotation angle data for different Laguerre-Gaussian modes taking the radius as a fitting parameter in the Mie-Debye theory of optical tweezers. We also discuss how micron-sized beads can be used as probes for optical aberrations introduced by the experimental setup. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2312_17332 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Precise in situ radius measurement of individual optically trapped microspheres using negative optical torque exerted by focused vortex beams Diniz, Kainã Schoger, Tanja Moura, Guilherme T. Fonseca, Arthur L. Ether Jr, Diney S. Dutra, Rafael S. Ingold, Gert-Ludwig Viana, Nathan B. Neto, Paulo A. Maia Optics Applied Physics We demonstrate a new method for determining the radius of micron-sized particles trapped by a vortex laser beam. The technique is based on measuring the rotation experienced by the center of mass of a microsphere that is laterally displaced by a Stokes drag force to an off-axis equilibrium position. The rotation results from an optical torque pointing along the direction opposite to the vortex beam angular momentum. We fit the rotation angle data for different Laguerre-Gaussian modes taking the radius as a fitting parameter in the Mie-Debye theory of optical tweezers. We also discuss how micron-sized beads can be used as probes for optical aberrations introduced by the experimental setup. |
| title | Precise in situ radius measurement of individual optically trapped microspheres using negative optical torque exerted by focused vortex beams |
| topic | Optics Applied Physics |
| url | https://arxiv.org/abs/2312.17332 |