Showing posts with label
IEEE Journal of Selected Topics in Quantum Electronics.
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Showing posts with label
IEEE Journal of Selected Topics in Quantum Electronics.
Show all posts
Qiangzhou Rong; Yajie Wang; Zhihua Shao; Xueguang Qiao
Large diameter fiber-optics tweezers are proposed in this paper, and their ability to trap and deliver Escherichia coli ( E. coli ) bacteria was characterized. The tweezers were formed by tapering four-mode fiber (FMF) with 8.7 μ m diameter, allowing the resonance field of the extended high-order modes to be used for manipulating the micro-objects. The diameter of the FMF taper was much larger than that of reported fiber-optic devices with nanoscale diameter, thereby making the device work as sturdier tweezers. The key factor for success is that, along the light transmission axis, the higher order modes have a unique mode field that extends longer and with a larger range around the fiber waist than the fundamental mode. At wavelengths ranging from 1500 to 1600 nm, especially close to 1560 nm, trapping and delivering of E. coli along the fiber was observed. In addition, a further demonstration for operation time shows a larger tapered fiber diameter was able to extend the service life of tweezers. The higher order micro-fiber modes offer a new opportunity for optical manipulation at the single-cell level.
DOI
Mostafa Ghorbanzadeh; Mohammad Kazem Moravvej-Farshi; Sara Darbari
An optophoresis system based on surface plasmons in a simple microfluidic environment is proposed, which introduces new functionalities, including three -dimensional trapping of particles, bidirectional manipulation, controllable sorting, and in situ sensing. Its operating principle is based on plasmonic field, which is excited by the Kretschmann configuration on a gold stripe. In this system, trapping, manipulating, and sorting mechanisms are based on the balance of two oppositely exerted scattering forces induced by two counter-propagating surface plasmons. Moreover, for detecting particle's intrinsic properties and in situ position monitoring, we take advantage of the particle's lens-like behavior and stripe's edge effects. The proposed low-power functional system that can be simply and inexpensively integrated into lab-on-a-chip devices is a promising candidate for biological applications and developing integrated optical manipulation chips.
DOI
Lu Sun ; Sinan Lai ; Chun Jiang
We present a study of transverse optical forces arising in a free-standing graphene nanoribbon pair. The force is evaluated using a numerical procedure based on finite difference time domain simulations. We find that optical forces on the order of nN·μm-1·mW-1 can be obtained in both vertically and horizontally aligned ribbon pair. The influence of graphene loss on the total optical force obtainable is also investigated in this paper. Numerical results show that we can get greater transverse optical force in a shorter actuation distance, considerably promising for nano-optomechanical applications.
DOI
Mostafa Ghorbanzadeh, Mohammad Moravvej-Farshi; Sara Darbari
An optophoresis system based on surface plasmons in a simple microfluidic environment is proposed, which introduces new functionalities, including three dimensional trapping of par-ticles, bidirectional manipulation, controllable sorting, and in-situ sensing. Its operating principle is based on plasmonic field, which is excited by the Kretschmann configuration on a gold stripe. In this system, trapping, manipulating, and sorting mech-anisms are based on the balance of two oppositely exerted scat-tering forces induced by two counter-propagating surface plas-mons. Moreover, for detecting particle’s intrinsic properties and in-situ position monitoring, we take advantage of the particle’s lens-like behavior and stripe’s edge effects. The proposed low power functional system that can be simply and inexpensively integrated into lab-on-a-chip devices is a promising candidate for biological applications and developing integrated optical manipu-lation chips.
Diane De Coster; Qing Liu; Michael Vervaeke; Jurgen Van Erps; Jeroen Missinne; Hugo Thienpont; Heidi Ottevaere
We present an optofluidic chip in polymethyl methacrylate (PMMA) that combines optical trapping of single particles with confocal Raman spectroscopy. We introduce the design of the optofluidic chip and the ray-tracing simulations combined with mathematical calculations used to determine the optical forces exerted on the particles and to model the excitation and collection of Raman scattering. The optical trapping is done using a single-beam gradient trap realized by a high numerical aperture free-form reflector, monolithically embedded in the optofluidic chip. The focused beam functions both as the excitation beam as well as the trapping beam. The embedded freeform reflector is also used to collect the Raman scattered light generated from the trapped particle. We discuss the fabrication process for the prototyping of the chip, which consists of an ultraprecision diamond turning step and a sealing step. Finally, we demonstrate the functionality of the optofluidic chip in a proof-of-concept experimental setup and trap polystyrene beads with diameters from 6 to 15m. We characterize the maximal transverse optical trap strength in the sample flow direction using the drag force method, measuring average efficiencies that lie between 0.11 and 0.36, and perform confocal Raman measurements of these particles.
DOI
Kisung Lee, Danilina, A.V. ; Kinnunen, M. ; Priezzhev, A.V. ; Meglinski, I.
The red blood cells (RBC) aggregation is of current basic science and clinical interest, as a determinant of blood microcirculation. Thus, the measurement and assessment of the RBC aggregation property (aggregability) and aggregation state at different physiologic conditions of a human individual or laboratory animal are an important issue. In this paper, in order to assess the dynamics of RBC interaction, optical tweezers were used to probe the forces during the RBC doublet formation or disruption. We show that in autologous plasma, RBC aggregating and disaggregating forces have different absolute values, ca 2-4 pN and dozens of piconewton, correspondingly. We speculate that in plasma, RBC aggregation and disaggregation processes have different driving forces.
DOI
Decombe, J., Mondal, S.K. ; Kumbhakar, D. ; Pal, S.S. ; Fick, J.
Optical trapping of dielectric microparticles is reported using an optical tweezers based on two original chemically etched fiber nanoantenna. The nanoantenna converts Gaussian beam into nondiffracting type quasi-Bessel beam, which is used in trapping microparticles. Stable trapping in three distinct positions is observed for an antenna distance of 32.5 $mu$m and for light powers as low as 1.3 mW. Optical trapping properties are studied by applying Boltzmann statistics to the particle position fluctuations. Harmonic trapping potentials with trap stiffness of 3.5 pN $mu$ m$^{-1}$ are observed. The FDTD simulation results on the antenna optics are also included to understand the trapping mechanism.
DOI
Poul M. Bendix, Liselotte Jauffred, Kamilla Norregaard, and Lene B. Oddershede
Optical manipulation of nanostructures offers new exciting possibilities for building new nano-architectures and for exploring the fundamental interactions between light and nanoparticles. The optical properties of nanostructures differ substantially from those of similar bulk material and exhibit an exquisite sensitivity on nanoparticle shape and composition. The plethora of particles available today expands the possibilities of optical manipulation to include control over particle temperature, luminescence, orientation, and even over the rotational optical momentum transferred to the nanoparticle. Here, we summarize recent experimental advances within optical manipulation of individual nanoparticles and quantum dots with a focus on resonant versus non-resonant trapping, optically induced heating, spherical aberration, and orientation control. Also, we present novel quantitative data on the photonic interaction between gold nanoshells and a focused laser beam. Lastly, promising applications of the biophotonical properties of nanoparticles within nanoscience and biophysics are pointed out.
DOI
Honglei Guo; Ping Zhao; Gaozhi Xiao; Zhiyi Zhang; Jianping Yao
An SU-8/PDMS microfluidic chip incorporating a monolithically integrated on-chip lens set for transport and manipulation of microparticles is developed. The components, including the on-chip lens set, the microfluidic channel, and the fiber grooves, are defined in a single layer of SU-8 by one-step photolithography. The design of the on-chip lens set and the fabrication of the microfluidic chip are fully described. The influence of the beam-waist radius on the manipulation performance is theoretically analyzed and experimentally verified for the first time. In the cross-type optofluidic architecture, the evaluation is performed by measuring the particle displacement with different beam-waist radii under different fluid-flow rates. The on-chip lens set is designed to have a specific dimension to achieve the required beam-waist radius. It is revealed that the particle displacement is counter-proportional to the beam-waist radius. An experiment is performed. The results show that the particle displacement is increased by reducing the beam-waist radius. The optical manipulation of microparticles is also demonstrated by using two counter-propagating light beams that are perpendicular to the fluid-flow direction with the beam-waist radius determined by two on-chip lens sets placed on the two sides of the microfluidic channel. The proposed architecture could be used to enhance the performance in particle transport, separation, and concentration.
DOI
Mthunzi, P.; Lee, W. M.; Riches, A.; Brown, C. T. A.; Gunn-Moore, F. J.; Dholakia, K.
Optical micromanipulation of transparent microparticles such as cellular materials relies upon the application of optical forces that are crucially dependent on the refractive index contrast between the particle and the surrounding medium. We briefly review the application of optical forces for cell manipulation and sorting, highlighting some of the key experiments over the last twenty years. We then introduce a new technique for enhancing the dielectric contrast of mammalian cells, which is a result of cells naturally taking up microspheres from their environment. We explore how these intracellular dielectric tags can influence the scattering and gradient forces upon these cells from an externally applied optical field. We show that intracellular polymer microspheres can serve as highly directional optical scatterers and that scattering forces can enable sorting through axial guiding onto laminin-coated glass coverslips upon which the selected cells adhere. Such internal dielectric tagging presents a simple, inexpensive, sterile technique to enhance optical manipulation procedures for cellular material and may enable new sorting techniques within microfluidic systems.
Miao , X. Wilson, B. K. Cao , G. Pun , S. H. Lin, L. Y.
We report long-range trapping of vanadium dioxide (VO2) and vanadium oxyhydroxide (H2V3O8) nanowires at a distance as large as 50 mu m outside the laser spot using plasmonic tweezers and controlled rotation of the nanowires by combining trapping with microfluidic drag force. The plasmonic tweezers are built upon a self-assembled gold nanoparticle array platform. In addition to the long-range trapping and rotation capability, the required optical intensity for the plasmonic tweezers to initiate trapping is much lower than that required by conventional optical tweezers for similar nanowires. We also investigate possible mechanisms for the unique long-range trapping of nanowires through performing control experiments.
