Design and Construction of Optical Tweezers

The method known as “optical tweezers”, first introduced by Arthur Ashkin in 1986, uses laser light to trap dielectric particles. The method is based in the fact that light has linear moment when acting on a particle, which is redirected when light is refracted by the particle.  The redirection of light causes a force on the particle trapping the particle in the brightest part of the beam. The tweezer system used in 2017 by a previous student focused one laser beam on one trapped particle. The trapping force and drag force were measured with the eventual goal of splitting the initial laser beam into two in order to trap multiple particles at once. In adding onto previous progress, the single laser setup was adapted to include an Acoustic-Optic-Modulator (AOM) which split the initial beam.