US 12,189,110 B2
Optical trap calibration apparatus and method based on variation of electric field by optical imaging of nanoparticle
Cuihong Li, Hangzhou (CN); Zhenhai Fu, Hangzhou (CN); Jing Jiang, Hangzhou (CN); Zhiming Chen, Hangzhou (CN); Yuanyuan Ma, Hangzhou (CN); and Huizhu Hu, Hangzhou (CN)
Assigned to ZHEJIANG LAB, Hangzhou (CN); and ZHEJIANG UNIVERSITY, Hangzhou (CN)
Filed by ZHEJIANG LAB, Zhejiang (CN); and ZHEJIANG UNIVERSITY, Zhejiang (CN)
Filed on Mar. 10, 2022, as Appl. No. 17/691,125.
Claims priority of application No. 202110445513.3 (CN), filed on Apr. 25, 2021.
Prior Publication US 2022/0350125 A1, Nov. 3, 2022
Int. Cl. G02B 21/32 (2006.01); G21K 1/00 (2006.01); G01N 15/00 (2006.01)
CPC G02B 21/32 (2013.01) [G21K 1/006 (2013.01); G01N 2015/0038 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An optical trap calibration apparatus based on variation of electric field by optical imaging of a nanoparticle, wherein the apparatus comprises a first laser, a second laser, a vacuum chamber, an objective lens, an electric field imposing unit, an electric field quantity control unit, a beam splitter, a filter unit, a convex lens, and an imager;
the beam splitter, the objective lens and the electric field imposing unit are sequentially arranged on an optical axis of the first laser; the vacuum chamber encompasses the objective lens and the electric field imposing unit, so as to provide a vacuum environment for the nanoparticle; the electric field imposing unit is externally connected to the electric field quantity control unit, and the electric field imposing unit can generate parallel electric fields in three directions of x, y and z;
an optical axis of the second laser is perpendicular to the optical axis of the first laser, and a point of intersection of the two optical axes coincides with a focal point of an optical potential well formed by the objective lens;
the filter unit, the convex lens and the imager are sequentially arranged on a reflection light path of the beam splitter, and the filter unit can isolate an emission wavelength of the first laser and transmit the emission wavelength of the second laser;
a calculation unit calculates, according to scattered light distribution of the nanoparticle recorded by the imager, changes in the centroid position of the nanoparticle under the action of different electric fields, and completes calibration according to a functional relationship between the changes in the centroid position and changes in the electric field quantity; and
the imager is placed in a black box to suppress stray light for the imager.