Interferometry for topographical diagnostics of RBCs in optical tweezers

Abstract

Simultaneous non-invasive trapping and topography of erythrocytes by interferometric fringe projection profilometry has been presented. Sinusoidal fringes were generated with the help of compact Michelson interferometer (CMI) developed by coating a thin reflective layer (~100µm) of Al 2 O 3 on one face of a cubic beam splitter. An external mirror was mounted on XYZ translational stage to control the fringe frequency and orientation. Red He-Ne laser was used to generate the sinusoidal probe -interferogram using CMI to project onto the green-laser (cw) trapped healthy and deceased RBCs separately. Information coded reflected interferograms exhibits characteristic fringe-deviation with respect to probe-pattern for both the healthy and defective RBCs. Fourier transform analysis was adopted to retrieve the phase-map which can be exploited for topography, size determination and refractive-index of RBC. Refractive-index change is directly related with hemoglobin concentration of RBCs at any specific physiological state and hence information about health status and disease progression can be anticipated.

Latest achievements in generalized Lorenz‐Mie theories: A commented reference database

“…Kumar et al . discussed the clustering of optically trapped large diameter plasmonic gold nanoparticles by laser beam of hybrid‐TEM laser mode. Theoretical evaluations of radiation forces were carried out by using a parabolic Gaussian‐ray model of a tightly focused laser beam.…”