Clustered Speckle in Optical Tweezers

J.P. STAFORELLI; J.M. BRITO; E. VERA; P. SOLANO; A. LENCINA

Lima

Congreso; VII REUNIÓN IBEROAMERICANA DE ÓPTICA - X ENCUENTRO LATINOAMERICANO DE ÓPTICA, LÁSERES Y SUS APLICACIONES; 2010

Speckle appears when a rough surface or a diffuser is coherently illuminated. If a multiple aperture pupil is placed somewhere after the diffuser, clustered speckle can be observed, regardless the optical field is in free propagation regime or it passes through an imaging system. Clustered speckles reduce light volumes several times when compared with usual speckles. Moreover, they have odd statistical properties which differentiate them from usual speckles. When the clustered speckles are imaged by an objective lens of a standard optical trapping system, light volumes can be even smaller than the focus of a Gaussian beam. Then, multiple and random trapping volume distributions can be created with this technique enabling different studies concerning optical binding and matter wave transport with random potentials having different statistical properties. In this work an in situ study of the clustered speckle 3D structure in an optical trap is presented. A qualitative analysis of the clustered speckles in optical tweezers relative to number of apertures and size is carried on. Besides, in the Rayleigh regime, a general quantitative method to define the trapping capability of an optical field is proposed and used to characterize the clustered speckles.in situ study of the clustered speckle 3D structure in an optical trap is presented. A qualitative analysis of the clustered speckles in optical tweezers relative to number of apertures and size is carried on. Besides, in the Rayleigh regime, a general quantitative method to define the trapping capability of an optical field is proposed and used to characterize the clustered speckles.