title: Transition of a particle between adjacent optical traps: a study using catastrophe theory.
abstract: In spite of the widespread use of optical tweezers as a quantitative tool to measure small forces, there exists no unambiguous and simple experimental method for either validating its theoretically predicted form or empirically parameterizing it over the entire range. This problem is addressed by studying the transition of a colloidal particle between two spatially separated optical traps. The transition as a function of the relative intensity of the traps and the separation between them reveals a formal resemblance to the "butterfly catastrophe" which also maps onto to phase transitions observed, for example, in ferroelectrics on a phenomenological level. The method has been used to experimentally determine the force-displacement curve for an optical trap over its entire range.
authors: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400-005, India.
authors: Deepak
authors: D
authors: Kumar
authors: Shankar
authors: S
authors: Ghosh
authors: S
authors: S
authors: Bhattacharya
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D017711:Nonlinear Dynamics; D052898:Optical Tweezers; D010316:Particle Size
chemical_list: D003102:Colloids