Abstract

We develop and test a thermally activated state transition technique for ultraweak force measurement. As a force sensor, the technique was demonstrated on a classical Brownian bead immersed in water and restrained by a bistable optical trap. A femto-Newton-level flow force imposed on this sensor was measured by monitoring changes in the transition rates of the bead hopping between two energy states. The treatment of thermal disturbances as a requirement instead of a limiting factor is the major feature of the technique, and provides a new strategy by which to measure other ultraweak forces beyond the thermal noise limit.

©2012 Optical Society of America

Femto-Newton light force measurement at the thermal noise limit

F. Mueller, S. Heugel, and L. J. Wang
Opt. Lett. 33(6) 539-541 (2008)

Sub-femto-Newton sensing torsion pendulum for detection of light force

Shengguo Guan, Jing Sun, Biao Huang, Yanbei Cheng, Zhenglu Duan, and Jianxin Le
Opt. Lett. 47(19) 4997-5000 (2022)

Acousto-optically generated potential energy landscapes: Potential mapping using colloids under flow

Michael P. N. Juniper, Rut Besseling, Dirk G. A. L. Aarts, and Roel P. A. Dullens
Opt. Express 20(27) 28707-28716 (2012)

Polarization phase-shifting Newton interferometer for plane optical surface measurements

Shyh-Tsong Lin, Liang-Chia Chen, Sheng-Lih Yeh, Hu’ng-Xuân Trinh, and Hung-Pin Chen
Opt. Lett. 37(4) 467-469 (2012)

Measurements of milli-Newton surface tension forces with tilted fiber Bragg gratings

Changyu Shen, Chuan Zhong, Dejun Liu, Xiaokang Lian, Jianyao Zheng, Jingjing Wang, Yuliya Semenova, Gerald Farrell, Jacques Albert, and John F. Donegan
Opt. Lett. 43(2) 255-258 (2018)