Using GPUs for Realtime Prediction of Optical Forces on Microsphere Ensembles

2012 ◽  
Author(s):  
Sujal Bista ◽  
Sagar Chowdhury ◽  
Satyandra K. Gupta ◽  
Amitabh Varshney
Keyword(s):  
Laser Beam ◽  
Optical Tweezers ◽  
Computational Models ◽  
Laser Beams ◽  
Cell Manipulation ◽  
Optical Traps ◽  
Optical Forces ◽  
Gaussian Laser Beam ◽  
Multiple Particles ◽  
Speed Up

Laser beams can be used to create optical traps that can hold and transport small particles. Optical trapping has been used in a number of applications ranging from prototyping at the microscale to biological cell manipulation. Successfully using optical tweezers requires predicting optical forces on the particle being trapped and transported. Reasonably accurate theory and computational models exist for predicting optical forces on a single particle in the close vicinity of a Gaussian laser beam. However, in practice the workspace includes multiple particles that are manipulated using individual optical traps. It has been experimentally shown that the presence of a particle can cast a shadow on a nearby particle and hence affect the optical forces acting on it. Computing optical forces in the presence of shadows in real-time is not feasible on CPUs. In this paper, we introduce a ray-tracing-based application optimized for GPUs to calculate forces exerted by the laser beams on microparticle ensembles in an optical tweezers system. When evaluating the force exerted by a laser beam on 32 interacting particles, our GPU-based application is able to get a 66-fold speed up compared to a single core CPU implementation of traditional Ashkin’s approach and a 10-fold speedup over its single core CPU-based counterpart.

Using GPUs for Realtime Prediction of Optical Forces on Microsphere Ensembles

2013 ◽  
Vol 13 (3) ◽  
Author(s):  
Sujal Bista ◽  
Sagar Chowdhury ◽  
Satyandra K. Gupta ◽  
Amitabh Varshney
Keyword(s):  
Laser Beam ◽  
Optical Tweezers ◽  
Computational Models ◽  
Laser Beams ◽  
Cell Manipulation ◽  
Optical Traps ◽  
Optical Forces ◽  
Gaussian Laser Beam ◽  
Multiple Particles ◽  
Speed Up

Laser beams can be used to create optical traps that can hold and transport small particles. Optical trapping has been used in a number of applications ranging from prototyping at the microscale to biological cell manipulation. Successfully using optical tweezers requires predicting optical forces on the particle being trapped and transported. Reasonably accurate theory and computational models exist for predicting optical forces on a single particle in the close vicinity of a Gaussian laser beam. However, in practice the workspace includes multiple particles that are manipulated using individual optical traps. It has been experimentally shown that the presence of a particle can cast a shadow on a nearby particle and hence affect the optical forces acting on it. Computing optical forces in the presence of shadows in real-time is not feasible on CPUs. In this paper, we introduce a ray-tracing-based application optimized for GPUs to calculate forces exerted by the laser beams on microparticle ensembles in an optical tweezers system. When evaluating the force exerted by a laser beam on 32 interacting particles, our GPU-based approach is able to get a 66-fold speed up compared to a single core CPU implementation of traditional Ashkin's approach and a 10-fold speedup over the single core CPU-based implementation of our approach.

scholarly journals Optical tweezers: theory and practice

2020 ◽  
Vol 135 (12) ◽  
Author(s):  
Giuseppe Pesce ◽  
Philip H. Jones ◽  
Onofrio M. Maragò ◽  
Giovanni Volpe
Keyword(s):  
Laser Beam ◽  
Optical Tweezers ◽  
Dipole Approximation ◽  
Theoretical Background ◽  
Theory And Practice ◽  
Optical Traps ◽  
General Description ◽  
Optical Forces ◽  
Holographic Optical Tweezers ◽  
Calibration Techniques

AbstractThe possibility for the manipulation of many different samples using only the light from a laser beam opened the way to a variety of experiments. The technique, known as Optical Tweezers, is nowadays employed in a multitude of applications demonstrating its relevance. Since the pioneering work of Arthur Ashkin, where he used a single strongly focused laser beam, ever more complex experimental set-ups are required in order to perform novel and challenging experiments. Here we provide a comprehensive review of the theoretical background and experimental techniques. We start by giving an overview of the theory of optical forces: first, we consider optical forces in approximated regimes when the particles are much larger (ray optics) or much smaller (dipole approximation) than the light wavelength; then, we discuss the full electromagnetic theory of optical forces with a focus on T-matrix methods. Then, we describe the important aspect of Brownian motion in optical traps and its implementation in optical tweezers simulations. Finally, we provide a general description of typical experimental setups of optical tweezers and calibration techniques with particular emphasis on holographic optical tweezers.

A model of Gaussian laser beam self-trapping in optical tweezers for nonlinear particles

2021 ◽  
Vol 53 (8) ◽  
Author(s):  
Quy Ho Quang ◽  
Thanh Thai Doan ◽  
Kien Bui Xuan ◽  
Thang Nguyen Manh
Keyword(s):  
Laser Beam ◽  
Optical Tweezers ◽  
Gaussian Laser Beam ◽  
Self Trapping

Relativistic self-focusing of a rippled laser beam in a plasma

1999 ◽  
Vol 62 (4) ◽  
pp. 389-396 ◽  
Author(s):  
M. V. ASTHANA ◽  
A. GIULIETTI ◽  
DINESH VARSHNEY ◽  
M. S. SODHA
Keyword(s):  
Refractive Index ◽  
Laser Beam ◽  
The Self ◽  
Laser Beams ◽  
Radial Dependence ◽  
Main Beam ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Saturation Effects ◽  
Paraxial Ray

This paper presents an analysis of the relativistic self-focusing of a rippled Gaussian laser beam in a plasma. Considering the nonlinearity as arising owing to relativistic variation of mass, and following the WKB and paraxial-ray approximations, the phenomenon of self-focusing of rippled laser beams is studied for arbitrary magnitude of nonlinearity. Pandey et al. [Phys. Fluids82, 1221 (1990)] have shown that a small ripple on the axis of the main beam grows very rapidly with distance of propagation as compared with the self-focusing of the main beam. Based on this analogy, we have analysed relativistic self-focusing of rippled beams in plasmas. The relativistic intensities with saturation effects of nonlinearity allow the nonlinear refractive index in the paraxial regime to have a slower radial dependence, and thus the ripple extracts relatively less energy from its neighbourhood.

scholarly journals Automated Indirect Transportation of Biological Cells with Optical Tweezers and a 3D Printed Microtool

2019 ◽  
Vol 9 (14) ◽  
pp. 2883 ◽  
Author(s):  
Songyu Hu ◽  
Heng Xie ◽  
Tanyong Wei ◽  
Shuxun Chen ◽  
Dong Sun
Keyword(s):  
Laser Beam ◽  
Optical Tweezers ◽  
High Precision ◽  
Optical Tweezer ◽  
Cell Manipulation ◽  
Laser Exposure ◽  
Direct Writing ◽  
Negative Effects ◽  
Direct Exposure ◽  
Direct Cell

Optical tweezers are widely used for noninvasive and precise micromanipulation of living cells to understand biological processes. By focusing laser beams on cells, direct cell manipulation with optical tweezers can achieve high precision and flexibility. However, direct exposure to the laser beam can lead to negative effects on the cells. These phenomena are also known as photobleaching and photodamage. In this study, we proposed a new indirect cell micromanipulation approach combined with a robot-aided holographic optical tweezer system and 3D nano-printed microtool. The microtool was designed with a V-shaped head and an optical handle part. The V-shaped head can push and trap different sizes of cells as the microtool moves forward by optical trapping of the handle part. In this way, cell exposure to the laser beam can be effectively reduced. The microtool was fabricated with a laser direct writing system by two-photon photopolymerization. A control strategy combined with an imaging processing algorithm was introduced for automated manipulation of the microtool and cells. Experiments were performed to verify the effectiveness of our approach. First, automated microtool transportation and rotation were demonstrated with high precision. Second, indirect optical transportations of cells, with and without an obstacle, were performed to demonstrate the effectiveness of the proposed approach. Third, experiments of fluorescent cell manipulation were performed to confirm that, indicated by the photobleaching effect, indirect manipulation with the microtool could induce less laser exposure compared with direct optical manipulation. The proposed method could be useful in complex biomedical applications where precise cell manipulation and less laser exposure are required.

scholarly journals Second harmonic generation of q-Gaussian laser beam in plasma channel created by ignitor heater technique

2019 ◽  
Vol 37 (2) ◽  
pp. 184-196 ◽  
Author(s):  
Naveen Gupta
Keyword(s):  
Second Harmonic Generation ◽  
Laser Beam ◽  
Harmonic Generation ◽  
Plasma Channel ◽  
Second Harmonic ◽  
Laser Beams ◽  
Theory Approach ◽  
Gaussian Laser Beam ◽  
Incident Laser ◽  
Pump Frequency

AbstractThis paper presents a scheme for second harmonic generation (SHG) of q-Gaussian laser beam in plasma channel created by ignitor heater technique. The ignitor beam creates plasma by tunnel ionization of air. The heater beam heats the plasma electrons and establishes a parabolic density profile. The third beam (q-Gaussian beam) is guided in this plasma channel under the combined effects of density nonuniformity of the plasma channel and relativistic mass nonlinearity of the plasma electrons. The propagation of q-Gaussian laser beam through the plasma channel excites an electron plasma wave at pump frequency that interacts with the incident laser beam to produce its second harmonics. The formulation is based on finding the numerical solution of the nonlinear Schrodinger wave equation for the fields of the incident laser beams with the help of moment theory approach. Particular emphasis is put on dynamical variations of the spot size of the laser beams and conversion efficiency of the second harmonics with distance of propagation.

scholarly journals Velocity-dependent optical forces and Maxwell’s demon

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
J. D. Franson
Keyword(s):  
Quantum Information ◽  
Laser Beam ◽  
Optical Tweezers ◽  
Optical Forces ◽  
Velocity Dependence ◽  
Photon Scattering ◽  
Maxwell’S Demon ◽  
Maxwell's Demon ◽  
Dipole Force ◽  
The Doppler Effect

Abstract An atom placed in a focused laser beam will experience a dipole force due to the gradient in the interaction energy, which is analogous to the well-known optical tweezers effect. This force will be dependent on the velocity of the atom due to the Doppler effect, which could potentially be used to implement a Maxwell’s demon. Photon scattering and other forms of dissipation can be negligibly small, which would seem to contradict quantum information proofs that a Maxwell’s demon must dissipate a minimum amount of energy. We show that the velocity dependence of the dipole force is cancelled out by another force that is related to the gradient in the phase of the laser beam. As a result, a Maxwell’s demon cannot be implemented in this way.

scholarly journals Tele–Robotic Platform for Dexterous Optical Single-Cell Manipulation

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 677 ◽  
Author(s):  
Edison Gerena ◽  
Florent Legendre ◽  
Akshay Molawade ◽  
Youen Vitry ◽  
Stéphane Régnier ◽  
...  
Keyword(s):  
Single Cell ◽  
Optical Tweezers ◽  
Biomedical Applications ◽  
High Speed ◽  
Cell Manipulation ◽  
Optical Traps ◽  
A Cell ◽  
Six Dof ◽  
Master Device ◽  
Single Cell Manipulation

Single-cell manipulation is considered a key technology in biomedical research. However, the lack of intuitive and effective systems makes this technology less accessible. We propose a new tele–robotic solution for dexterous cell manipulation through optical tweezers. A slave-device consists of a combination of robot-assisted stages and a high-speed multi-trap technique. It allows for the manipulation of more than 15 optical traps in a large workspace with nanometric resolution. A master-device (6+1 degree of freedom (DoF)) is employed to control the 3D position of optical traps in different arrangements for specific purposes. Precision and efficiency studies are carried out with trajectory control tasks. Three state-of-the-art experiments were performed to verify the efficiency of the proposed platform. First, the reliable 3D rotation of a cell is demonstrated. Secondly, a six-DoF teleoperated optical-robot is used to transport a cluster of cells. Finally, a single-cell is dexterously manipulated through an optical-robot with a fork end-effector. Results illustrate the capability to perform complex tasks in efficient and intuitive ways, opening possibilities for new biomedical applications.

scholarly journals Generation of Hybrid Optical Trap Array by Holographic Optical Tweezers

2021 ◽  
Vol 9 ◽  
Author(s):  
Xing Li ◽  
Yuan Zhou ◽  
Yanan Cai ◽  
Yanan Zhang ◽  
Shaohui Yan ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Optical Trap ◽  
Optical Traps ◽  
Axial Position ◽  
Spatial Light Modulators ◽  
Light Modulators ◽  
Multiple Particles ◽  
Holographic Optical Tweezers ◽  
Almost All ◽  
Gaussian Point

Enabled by multiple optical traps, holographic optical tweezers can manipulate multiple particles in parallel flexibly. Spatial light modulators are widely used in holographic optical tweezers, in which Gaussian point (GP) trap arrays or special mode optical trap arrays including optical vortex (OV) arrays, perfect vortex (PV) arrays, and Airy beam arrays, etc., can be generated by addressing various phase holograms. However, the optical traps in these arrays are almost all of the same type. Here, we propose a new method for generating a hybrid optical trap array (HOTA), where optical traps such as GPs, OVs, PVs, and Airy beams in the focal plane are combined arbitrarily. Also, the axial position and peak intensity of each them can be adjusted independently. The energy efficiency of this method is theoretically studied, while different micro-manipulations on multiple particles have been realized with the support of HOTA experimentally. The proposed method expands holographic optical tweezers’ capabilities and provides a new possibility of multi-functional optical micro-manipulation.

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