Jonathan Nylk, Martin V. G. Kristensen, Michael Mazilu, Anisha K. Thayil, Claire A. Mitchell, Elaine C. Campbell, Simon J. Powis, Frank J. Gunn-Moore, and Kishan Dholakia.

Biomedical Optics Express 6(4), 1512-1519 (2015)

doi: 10.1364/BOE.6.001512

We demonstrate a miniaturized single beam fiber optical trapping probe based on a high numerical aperture graded index (GRIN) micro-objective lens. This enables optical trapping at a distance of 200μm from the probe tip. The fiber trapping probe is characterized experimentally using power spectral density analysis and an original approach based on principal component analysis for accurate particle tracking. Its use for biomedical microscopy is demonstrated through optically mediated immunological synapse formation.