Continuous-wave self-focusing and self-trapping of light in artificial Kerr media
TL;DR: The independence of the critical power for self-trapping on the beam diameter in the unsaturated regime was confirmed for the first time to the authors' knowledge and values of the nonlinear coefficient were determined.
Abstract: Artificial Kerr media made from liquid suspensions of submicrometer particles were used as a new type of nonlinear medium for observing cw self-focusing and self-trapping of laser beams. Self-trapping of TEM00-mode beams and higher-order TEM01- and TEM01*-mode beams were investigated. Saturation-free operation down to filament diameters of ~2 μm was observed. The independence of the critical power for self-trapping on the beam diameter in the unsaturated regime was confirmed for the first time to our knowledge. Values of the nonlinear coefficient were determined for a range of particle diameters from 0.038 to 0.234 μm.
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TL;DR: Theoretical expressions of the radiation pressure force for a dielectric sphere in the Rayleigh regime of light scattering under illumination of a Gaussian laser beam with the fundamental mode are derived in explicit form as a function of measurable quantities of the beam parameter in MKS units as mentioned in this paper.
789 citations
TL;DR: In this article, the importance of exploring the optically mediated interaction between assembled objects that can cause attractive and repulsive forces and dramatically influence the way they assemble and organize themselves is discussed.
Abstract: The light-matter interaction has been at the heart of major advances from the atomic scale right to the microscopic scale over the past four decades. Confinement by light, embodied by the area of optical trapping, has had a major influence across all of the natural sciences. However, an emergent and powerful topic within this field that has steadily merged but not gained much recognition is optical binding: the importance of exploring the optically mediated interaction between assembled objects that can cause attractive and repulsive forces and dramatically influence the way they assemble and organize themselves. This offers routes for colloidal self-assembly, crystallization, and organization of templates for biological and colloidal sciences. In this Colloquium, this emergent area is reviewed looking at the pioneering experiments in the field and the various theoretical approaches that aim to describe this behavior. The latest experimental studies in the field are reviewed and theoretical approaches are now beginning to converge to describe the binding behavior seen. Recent links between optical binding and nonlinearity are explored as well as future themes and challenges.
430 citations
Cites background or methods from "Continuous-wave self-focusing and s..."
...This realization led to various experiments with colloidal suspensions that included four-wave mixing Smith et al., 1981 , self-focusing optical beams Ashkin et al., 1982 , optical spatial soliton OSS propagation Yashin et al., 2005 , and modulation instability MI Reece et al., 2007 ....
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...They occur as a result of the balance between diffraction and nonlinearity connected with the refractive index increase in the high-intensity parts of the optical field that results in self-focusing under intense illumination Ashkin et al., 1982 ....
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...We know from the early work of Ashkin and Smith how colloidal particles can act as nonlinear media Ashkin et al., 1982; Smith et al., 1982 : with optical forces pulling particles into bright field lines one can see how a modulation of the refractive index might occur in such systems....
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TL;DR: In this article, the authors discuss self-focusing of spatial optical solitons in diffractive nonlinear media due to either transverse (one more unbounded spatial dimension) or modulational (induced by temporal wave dispersion) instabilities, in the framework of the cubic nonlinear Schrodinger equation and its generalizations.
356 citations
TL;DR: Single-walled carbon nanotubes have a fast saturable absorption over a broad wavelength range, and the demonstrated technique is an extremely simple and inexpensive method for making fiber-integrated, saturable absorbers for passive modelocking of fiber lasers.
Abstract: Optical radiation propagating in a fiber is used to deposit commercially available, single-walled carbon nanotubes on cleaved optical fiber end faces and fiber connectors. Thermophoresis caused by heating due to optical absorption is considered to be a likely candidate responsible for the deposition process. Single-walled carbon nanotubes have a fast saturable absorption over a broad wavelength range, and the demonstrated technique is an extremely simple and inexpensive method for making fiber-integrated, saturable absorbers for passive modelocking of fiber lasers. Pulse widths of 247 fs are demonstrated from an erbium-doped fiber laser operating at 1560 nm, and 137 fs pulses are demonstrated from an amplified Yb-doped fiber laser at 1070 nm.
231 citations
03 Jun 2021
TL;DR: In this paper, the authors summarize the recent advances in the field of optical tweezers using structured light beams with customized phase, amplitude, and polarization in 3D optical trapping.
Abstract: Optical trapping describes the interaction between light and matter to manipulate micro-objects through momentum transfer. In the case of 3D trapping with a single beam, this is termed optical tweezers. Optical tweezers are a powerful and noninvasive tool for manipulating small objects, and have become indispensable in many fields, including physics, biology, soft condensed matter, among others. In the early days, optical trapping was typically accomplished with a single Gaussian beam. In recent years, we have witnessed rapid progress in the use of structured light beams with customized phase, amplitude, and polarization in optical trapping. Unusual beam properties, such as phase singularities on-axis and propagation invariant nature, have opened up novel capabilities to the study of micromanipulation in liquid, air, and vacuum. We summarize the recent advances in the field of optical trapping using structured light beams.
215 citations
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1,650 citations
TL;DR: Use of lasers has revolutionized the study and applications of radiation pressure, and it is now possible to optically accelerate, slow, stably trap, and manipulate micrometer-sized dielectric particles and atoms.
Abstract: Use of lasers has revolutionized the study and applications of radiation pressure. Light forces have been achieved which strongly affect the dynamics of individual small particles. It is now possible to optically accelerate, slow, stably trap, and manipulate micrometer-sized dielectric particles and atoms. This leads to a diversity of new scientific and practical applications in fields where small particles play a role, such as light scattering, cloud physics, aerosol science, atomic physics, quantum optics, and high-resolution spectroscopy.
559 citations
TL;DR: In this paper, steady-state self-focusing, self-trapping, and self-defocusing of a cw dye laser beam in sodium vapor for frequencies within several Doppler widths of the $D$-line resonance transitions were reported.
Abstract: We report steady-state self-focusing, self-trapping, and self-defocusing of a cw dye laser beam in sodium vapor for frequencies within several Doppler widths of the $D$-line resonance transitions. We measured the variation of the beam profile as the light propagates through the vapor. We observed a 20-mW beam self-trapped in a 12-cm-long filament having a half-power diameter of 70 \ensuremath{\mu}m.
259 citations
TL;DR: In this article, deegenerate four-wave mixing experiments have been performed using a liquid suspension of 0.234-μm-diameter latex spheres as the nonlinear medium.
Abstract: Degenerate four-wave mixing experiments have been performed using a liquid suspension of 0.234-μm-diameter latex spheres as the nonlinear medium. The measured effective optical Kerr coefficient, n2, is 3.6 × 10−3 (MW/cm2)−1. This is ~105× the value for CS2. Measured grating reflectivity, formation, and decay times are in reasonable agreement with a simple model assuming Rayleigh scattering and Brownian diffusion.
196 citations
154 citations