ISSN 1063-7850, Technical Physics Letters, 2014, Vol. 40, No. 6, pp. 495–498. © Pleiades Publishing, Ltd., 2014. Original Russian Text © G.S. Sokolovskii, S.N. Losev, K.K. Soboleva, V.V. Dyudelev, A.G. Deryagin, W. Sibbett, V.I. Kuchinskii, E.U. Rafailov, 2014, published in Pis’ma v Zhurnal Tekhnicheskoi Fiziki, 2014, Vol. 40, No. 11, pp. 53–59. 495 Recently, much interest has been shown in Bessel light beams because of their ability to propagate at large distances without divergence [1]; i.e., they are very promising for devices designed at manipulating microscopic and nanoscale objects (the so-called optical tweezers [2, 3]), controlling micromachines [4], and some other applications. Bessel beams can be formed by transforming Gaussian beams, passing them through an axicon (conical lens) [5, 6]. When a light wave passes through an axicon, it is refracted and interferes so that its radial intensity distribution is described by the first-kind Bessel function of zero order [5]. Projection of a Bessel beam on a screen appears to be a bright spot surrounded by a system of concentric rings. The number of rings and the propa- gation length of the nondivergent beam are deter- mined by the aperture and axicon vertex angle. For spatial propagation, the central maximum of the inter- ference pattern retains the same width with weak intensity oscillations, thus providing energy transfer over large distances. It was believed for a long time that the formation of Bessel beams requires highly coherent light sources; therefore, they can only be generated by gas and solid- state lasers. Thus, optical tweezers based on Bessel beams appeared to be cumbersome and expensive tools. However, it was shown a few years ago [7] that, with strong orificing, one can form invariant light beams even from a halogen lamp (which is an incoher- ent light source). Although orificing leads to signifi- cant optical loss and, thus, reduces the light power in the central spot of the Bessel beam generated in this way to an unacceptably low level, groundbreaking work by Fisher et al. [7] inspired many studies in this field. In particular, Bessel beams from LEDs [8] and wide-stripe semiconductor lasers [9] have been dem- onstrated recently. The next important steps to practi- cal application of Bessel beams from semiconductor light sources were the establishment of the importance of spatial (rather than temporal) coherence of the light source used to generate Bessel beams [10]; the study of the influence of beam-propagation parameter M 2 (the ratio of the beam divergence to the divergence of ideal Gaussian beam, determined by the diffraction limit [11]) on the Bessel-beam propagation [12]; and the demonstration of Bessel beams with a power up to sev- eral watts [13], which is sufficient for the overwhelm- ing majority of practical applications. In this paper, we report (for the first time, to the best of our knowledge) on the use of Bessel beams from semiconductor lasers for optical capture and manipulation of microscopic particles (including liv- ing cells). A schematic of the experimental setup is shown in Fig. 1. Bessel beams were generated by a 1065-nm semiconductor laser with a Fabry–Perot cavity and fiber output. The fiber output provided a symmetric directional light pattern. The power at the fiber output was up to 600 mW. The laser beam was collimated and focused by an optical system com- posed of several alternating microlenses with magnifi- cations from 8 to 40; these lenses were mounted on micropositioners. The Bessel beam was formed by an axicon with a vertex angle of 160°, which determined the transverse size (~7 μm) of the central part of the Bessel beam. The Bessel beam size was measured using a transparent calibrated grid (the so-called graticule) Manipulation of Microparticles Using Bessel Beams from Semiconductor Lasers G. S. Sokolovskii, S. N. Losev, K. K. Soboleva, V. V. Dyudelev, A. G. Deryagin, W. Sibbett, V. I. Kuchinskii, and E. U. Rafailov Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg, 194021 Russia e-mail: gs@mail.ioffe.ru St. Petersburg State Polytechnical University, St. Petersburg, 195251 Russia School of Physics and Astronomy, University of St. Andrews, St. Andrews, UK LETI St. Petersburg State Electrotechnical University, St. Petersburg, 197376 Russia Aston Institute of Photonic Technologies, Aston University, Birmingham, UK Received February 7, 2014 Abstract—Optical manipulation of microscopic objects (including living cells) using Bessel beams from semiconductor lasers has been shown for the first time. In addition, it has been found in the experiments that a Bessel beam of sufficient power from a semiconductor laser makes it possible to manipulate simultaneously several microscopic objects captured into its central spot and the first ring. DOI: 10.1134/S1063785014060133