Generation of Complex Transverse Energy Flow Distributions with Autofocusing Optical Vortex Beams

Author(s):

Khonina, Svetlana N.; Porfirev, Alexey P.; Ustinov, Andrey V. & Butt, Muhammad Ali

Abstract:

“Optical vortex (OV) beams are widely used for the generation of light fields with transverse energy flow inducing orbital motion of the nano- and microparticles in the transverse plane. Here, we present some new modifications of OV beams with autofocusing properties for shaping complex transverse energy flow distributions varying in space. The angular component of the complex amplitude of these beams is defined by the superpositions of OV beams with different topological charges. The proposed approach provides a convenient method to control the three-dimensional structure of the generated autofocusing OV beams. The control of the transverse distribution of an autofocusing beam provides a wide variety of generated fields with both rotating and periodic properties, which can be used in the field of laser manipulation and laser material processing. Thus, the obtained numerical results predict different types of motion of the trapped particles for the designed OV autofocusing beams. The experimental results agree with modeling results and demonstrate the principal possibility to shape such laser beams using spatial light modulators.”

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Publication: Micromachines
Issue/Year: Micromachines, Volume 12; Number 3; Pages 297; 2021
DOI: 10.3390/mi12030297

Experimental optical trapping of micro-particles with Frozen Waves

Author(s):

Rafael A. B. Suarez and Antonio A. R. Neves and Marcos R. R. Gesualdi and Leonardo A. Ambrosio and Michel Zamboni-Rached

Abstract:

“This work presents the first optical trapping experimental demonstration of micro-particles with Frozen Waves. Frozen Waves are an efficient method to model longitudinally the intensity of non-diffracting beams obtained by superposing co-propagating Bessel beams with the same frequency and order. The experimental setup of a holographic optical tweezers using spatial light modulators has been assembled and optimized. We investigate the optical force distribution acting on micro-particles of two types of Frozen Waves.The results show that it is possible to obtain greater stability for optical trapping using Frozen Waves. The significant enhancement in trapping geometry from this approach shows promising applications for optical tweezers, micro-manipulations over a broad range. ”

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Publication: Optics Letters
Issue/Year: Vol. 45, Issue 9, pp. 2514-2517
DOI: 10.1364/OL.390909

Rapid tilted-plane Gerchberg-Saxton algorithm for holographic optical tweezers

Author(s):

Yanan Cai, Shaohui Yan, Zhaojun Wang, Runze Li, Yansheng Liang, Yuan Zhou, Xing Li, Xianghua Yu, Ming Lei and Baoli Yao

Abstract:

“Benefitting from the development of commercial spatial light modulator (SLM), holographic optical tweezers (HOT) have emerged as a powerful tool for life science, material science and particle physics. The calculation of computer-generated holograms (CGH) for generating multi-focus arrays plays a key role in HOT for trapping of a bunch of particles in parallel. To realize dynamic 3D manipulation, we propose a new tilted-plane GS algorithm for fast generation of multiple foci. The multi-focal spots with a uniformity of 99% can be generated in a tilted plane. The computation time for a CGH with 512512 pixels is less than 0.1 second.
We demonstrated the power of the algorithm by simultaneously trapping and rotating silica beads with a 77 spots array in three dimensions. The presented algorithm is expected as a powerful kernel of HOT.”

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Publication: Optics Express
Issue/Year: Vol. 28, Issue 9, pp. 12729-12739
DOI: 10.1364/OE.389897

Generation of Tunable Fractional Vector Curvilinear Beams With Controllable Phase Distribution

Author(s):

Fengyan Gu, Zhongzheng Gu, Chenliang Chang, Caojin Yuan, Shaotong Feng, Fangjian Xing and Shouping Nie

Abstract:

“An approach to generate the tunable fractional vector curvilinear beams (VCBs) was proposed. The scheme is based on the vector optical field generator (VOFG) system, where the two orthogonal polarized scalar curvilinear beams (SCBs) are generated to be the base vector components, and coaxially superposed by a Ronchi grating. We design a new phase distribution with several loops of 0 to π in order to generate more dark gaps. The phase distribution becomes nonuniform by varying the phase variation rate and the positions of the dark gaps are changed. Using the different parameters of the curves, the fractional VCBs with different shapes are achieved. The two orthogonal polarized SCBs with the opposite topological charges are modulated to perform the beam conversion by a phase-only computer-generated hologram (CGH). Our experimental results comply with the theory and the radial opening of the dark gaps may have some applications for guiding and transporting particles.”

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Publication: IEEE Photonics Journal
Issue/Year: Volume: 11 Issue: 6 (2019)
DOI: 10.1109/JPHOT.2019.2942041

Generation of reconfigurable optical traps for microparticles spatial manipulation through dynamic split lens inspired light structures

Author(s):

Angel Lizana and Haolin Zhang and Alex Turpin and Albert Van Eeckhout and Fabian A. Torres-Ruiz and Asticio Vargas and Claudio Ramirez and Francesc Pi and Juan Campos

Abstract:

“We present an experimental method, based on the use of dynamic split-lens configurations, useful for the trapping and spatial control of microparticles through the photophoretic force. In particular, the concept of split-lens configurations is exploited to experimentally create customized and reconfigurable three-dimensional light structures, in which carbon coated glass microspheres, with sizes in a range of 63–75 μm, can be captured. The generation of light spatial structures is performed by properly addressing phase distributions corresponding to different split-lens configurations onto a spatial light modulator (SLM). The use of an SLM allows a dynamic variation of the light structures geometry just by modifying few control parameters of easy physical interpretation. We provide some examples in video format of particle trapping processes. What is more, we also perform further spatial manipulation, by controlling the spatial position of the particles in the axial direction, demonstrating the generation of reconfigurable three-dimensional photophoretic traps for microscopic manipulation of absorbing
particles.”

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Publication: Scientific Reports
Issue/Year: Scientific Reports volume 8, Article number: 11263 (2018)
DOI: 10.1038/s41598-018-29540-1

Micro-Dumbbells—A Versatile Tool for Optical Tweezers

Author(s):

Weronika Lamperska, Sławomir Drobczyński, Michał Nawrot, Piotr Wasylczyk, Jan Masajada

Abstract:

“Manipulation of micro- and nano-sized objects with optical tweezers is a well-established, albeit still evolving technique. While many objects can be trapped directly with focused laser beam(s), for some applications indirect manipulation with tweezers-operated tools is preferred. We introduce a simple, versatile micro-tool operated with holographic optical tweezers. The 40 µm long dumbbell-shaped tool, fabricated with two-photon laser 3D photolithography has two beads for efficient optical trapping and a probing spike on one end. We demonstrate fluids viscosity measurements and vibration detection as examples of possible applications.”

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Publication: Micromachines
Issue/Year: Micromachines Volume 9, Issue 6
DOI: 10.3390/mi9060277

Particle trapping and conveying using an optical Archimedes’ screw

Author(s):

Barak Hadad and Sahar Froim and Harel Nagar and Tamir Admon and Yaniv Eliezer and Yael Roichman and Alon Bahabad

Abstract:

“Trapping and manipulation of particles using laser beams has become an important tool in diverse fields of research. In recent years, particular interest has been devoted to the problem of conveying optically trapped particles over extended distances either downstream or upstream of the direction of photon momentum flow. Here, we propose and experimentally demonstrate an optical analog of the famous Archimedes’ screw where the rotation of a helical-intensity beam is transferred to the axial motion of optically trapped micrometer-scale, airborne, carbon-based particles. With this optical screw, particles were easily conveyed with controlled velocity and direction, upstream or downstream of the optical flow, over a distance of half a centimeter. Our results offer a very simple optical conveyor that could be adapted to a wide range of optical trapping scenarios.”

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Publication: Optica
Issue/Year: Optica Vol. 5, Issue 5, pp. 551-556 (2018)
DOI: 10.1364/OPTICA.5.000551

Investigation of albumin-derived perfluorocarbon-based capsules by holographic optical trapping

Author(s):

Jannis Köhler and Jegor Ruschke and Katja Bettina Ferenz and Cemal Esen and Michael Kirsch and Andreas Ostendorf

Abstract:

“Albumin-derived perfluorocarbon-based capsules are promising as artificial oxygen carriers with high solubility. However, these capsules have to be studied further to allow initial human clinical tests. The aim of this paper is to provide and characterize a holographic optical tweezer to enable contactless trapping and moving of individual capsules in an environment that mimics physiological (in vivo) conditions most effectively in order to learn more about the artificial oxygen carrier behavior in blood plasma without recourse to animal experiments. Therefore, the motion behavior of capsules in a ring shaped or vortex beam is analyzed and optimized on account of determination of the optical forces in radial and axial direction. In addition, due to the customization and generation of dynamic phase holograms, the optical tweezer is used for first investigations on the aggregation behavior of the capsules and a statistical evaluation of the bonding in dependency of different capsule sizes is performed. The results show that the optical tweezer is sufficient for studying individual perfluorocarbon-based capsules and provide information about the interaction of these capsules for future use as artificial oxygen carriers.”

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Publication: Biomed. Opt. Express
Issue/Year: Biomedical Optics Express Vol. 9,Issue 2, pp. 743-754(2018)
DOI: 10.1364/BOE.9.000743

Rotating of low-refractive-index microparticles with a quasi-perfect optical vortex

Author(s):

Yansheng Liang and Ming Lei and Shaohui Yan and Manman Li and Yanan Cai and Zhaojun Wang and Xianghua Yu and Baoli Yao

Abstract:

“Low-refractive-index microparticles, such as hollow microspheres, have shown great significance in some applications, such as biomedical sensing and targeted drug delivery. However, optical trapping and manipulation of low-refractive-index microparticles are challenging, owing to the repelling force exerted by typical optical traps. In this paper, we demonstrated optical trapping and rotating of large-sized low-refractive-index microparticles by using quasi-perfect optical vortex (quasi-POV) beams, which were generated by Fourier transform of high-order quasi-Bessel beams. Numerical simulation was carried out to characterize the focusing property of the quasi-POV beams. The dynamics of low-refractive-index microparticles in the quasi-POV with various topological charges was investigated in detail. To improve the trapping and rotating performances of the vortex, a point trap was introduced at the center of the ring. Experimental results showed that the quasi-POV was preferable for manipulation of large-sized low-refractive-index microparticles, with its control of the particles’ rotating velocity dependent only on the topological charge due to the unchanged orbital radius.”

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Publication: Applied Optics
Issue/Year: Applied Optics Volume 57, Issue 1 pp. 79-84
DOI: 10.1364/ao.57.000079

Fast label-free microscopy technique for 3D dynamic quantitative imaging of living cells

Author(s):

José A. Rodrigo, Juan M. Soto, and Tatiana Alieva

Abstract:

“The refractive index (RI) is an important optical characteristic that is often exploited in label-free microscopy for analysis of biological objects. A technique for 3D RI reconstruction of living cells has to be fast enough to capture the cell dynamics and preferably needs to be compatible with standard wide-field microscopes. To solve this challenging problem, we present a technique that provides fast measurement and processing of data required for real-time 3D visualization of the object RI. Specifically, the 3D RI is reconstructed from the measurement of bright-field intensity images, axially scanned by a high-speed focus tunable lens mounted in front of a sCMOS camera, by using a direct deconvolution approach designed for partially coherent light microscopy in the non-paraxial regime. Both the measurement system and the partially coherent illumination, that provides optical sectioning and speckle-noise suppression, enable compatibility with wide-field microscopes resulting in a competitive and affordable alternative to the current holographic laser microscopes. Our experimental demonstrations show video-rate 3D RI visualization of living bacteria both freely swimming and optically manipulated by using freestyle laser traps allowing for their trapping and transport along 3D trajectories. These results prove that is possible to conduct simultaneous 4D label-free quantitative imaging and optical manipulation of living cells, which is promising for the study of the cell biophysics and biology.”

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Publication: Optics Express
Issue/Year: Optics Express Volume 8, Issue 12
DOI: 10.1364/BOE.8.005507
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