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Significantly Improved Trapping Lifetime of Nanoparticles in an Optical Trap using Feedback Control



Arvind K. Balijepalli, Thomas W. LeBrun, Jason J. Gorman


We demonstrate an increase in trapping lifetime for optically trapped nanoparticles by more than an order of magnitude using feedback control. This has been demonstrated through simu- lation and experimental results for 100, nm gold particles and 350 nm silica particles. Trapping lifetimes have been substantially improved with little or no increase in beam intensity. No par- ticle escapes were detected with the controller on, leading to lower limits on the increase in lifetime for the 100 nm gold particles of 26 times (at constant beam power) and 22 times for the 350 nm silica particles (with beam power reduced by one third during controlled trapping). The approach described here can be combined with other techniques such as counter propagating beams or higher-order modes, and can be used to reduce optical heating of particles that are susceptible to photodamage, such as biological systems.
Nano Letters


Controlled optical traps, nanomanipulation, nanoparticles, FPGA, trap lifetime
Created April 10, 2012, Updated February 19, 2017