Open AccessRealization of pitch-rotational torque wrench in two-beam optical tweezers
Author(s) -
Muruga Lokesh,
Rahul Vaippully,
Vidya Bhallamudi,
Anil Prabhakar,
Basudev Roy
Publication year - 2021
Publication title -
journal of physics communications
Language(s) - English
Resource type - Journals
ISSN - 2399-6528
DOI - 10.1088/2399-6528/ac3a96
Subject(s) - optical tweezers , tweezers , optics , rotation (mathematics) , torque , physics , drag , spinning , birefringence , isotropy , rotation around a fixed axis , beam (structure) , particle (ecology) , materials science , mechanics , classical mechanics , computer science , oceanography , artificial intelligence , composite material , thermodynamics , geology
3D Pitch (out-of-plane) rotational motion has been generated in spherical particles by maneuvering the laser spots of holographic optical tweezers. However, since the spherical particles, which are required to minimise drag are perfectly isotropic, a controllable torque cannot be applied with it. It remains free to spin about any axis even after moving the tweezers beams. It is here that we trap birefringent particles of about 3 μ m diameter in two tweezers beams and then change the depth of one of the beam foci controllably to generate a pitch rotational torque-wrench and avoid the free spinning of the particle. We also detect the rotation with newly developed pitch motion detection technique and apply controlled torques on the particle.