Manipulation Of Optical Fields Research Articles

Multifunctional Meta-Devices for Full-Polarization Rotation and Focusing in the Near-Infrared

The creation of multi-channel focused beams with arbitrary polarization states and their corresponding optical torques finds effective applications in the field of optical manipulation at the micro-nanoscale. The existing metasurface-based technologies for polarization rotation have made some progress, but they have been limited to single functions and have not yet achieved the generation of full polarization. In this work, we propose a multi-channel and spatial-multiplexing interference strategy for the generation of multi-channel focusing beams with arbitrary polarization rotation based on all-dielectric birefringent metasurfaces via simultaneously regulating the propagation phase and the geometric phase and independently controlling the wavefronts at different circular polarizations. For the proof of concept, we demonstrate highly efficient multi-channel polarization rotation meta-devices. The meta-devices demonstrate ultra-high polarization extinction ratios and high focusing efficiencies at each polarization channel. Our work provides a compact and versatile wavefront-shaping methodology for full-polarization control, paving a new path for planar multifunctional meta-optical devices in optical manipulation at micro–nano dimensions.

Optical switch based on tunable perfect photon absorption

We investigate the manipulation of optical field within quantum electrodynamics (QED) scheme. In our proposal, the cold three-level atoms interact with a two-sided cavity driven by two coherent beams with a relative phase. Coherent perfect absorption (CPA) appears when the beams are in phase. However, the perfect outputs occur when the beams are out of phase. On the basis of the phase modulation, an optical switch can be operated at a high efficiency. With a coherent control laser, the excited and metastable levels of the atoms are coupled. Electromagnetically induced transparency (EIT) is produced at two-photon resonance, which leads to four-band CPA. By virtue of the control laser, the switching efficiency can be maximized in a weaker probe field, which provides advantages over two-level atoms on weak-signal switching.

Dual interface trapezium liquid prism with beam steering function.

In this paper, a dual interface trapezium liquid prism with beam steering function is implemented and analyzed. The electrowetting-on-dielectric method is used to perform the desired beam steering function without mechanical moving parts. This work examines deflection angles at different applied voltages to determine the beam steering range. The deflection angle can be experimentally measured from 0° to 3.43°. The proposed liquid prism can be applied in the field of optical manipulation, solar collecting system and so on.

Research Progress of the Label-Free Microscopy Based on Manipulation of Optical Field with Thin Films (Invited)

Research Progress of the Label-Free Microscopy Based on Manipulation of Optical Field with Thin Films (Invited)

Metasurfaces toward Optical Manipulation Technologies for Quantum Precision Measurement

AbstractMetasurface‐based optical field manipulation has significantly broadened the application range of micro‐optical components and integrated optics, gradually replacing bulky and complicated optical components. With the continuous development of micro and nano processing technology as well as computational analysis technology, metasurfaces have progressively shown their superior application prospects. After demonstrating tremendous results in classical optical applications, their application range has now extended to the field of quantum sensing. Due to their unique properties, such as small planar size, easy integration, flexible performance design, and tunable functionality, they have opened up a series of novel and rich applications for generating, manipulating, controlling, and detecting optical fields. In this paper, the basic principle and implementation of quantum measurement are presented and an overview of the design principles of metasurfaces, along with a summary of the latest advancements and potential applications of these surfaces in optical field modulation techniques for quantum precision measurement. Additionally, a thorough discussion and analysis of the challenges encountered by metasurfaces and their future development prospects is provided. Metasurfaces offer brand‐new opportunities for low‐cost, high‐performance, multifunctional miniaturized quantum sensors and are expected to play a significant role in the development of next‐generation quantum sensors.

Vector vortex beams sorting of 120 modes in visible spectrum

Abstract Polarization (P), angular index (l), and radius index (p) are three independent degrees of freedom (DoFs) of vector vortex beams, which have found extensive applications in various domains. While efficient sorting of a single DoF has been achieved successfully, simultaneous sorting of all these DoFs in a compact and efficient manner remains a challenge. In this study, we propose a beam sorter that simultaneously handles all the three DoFs using a diffractive deep neural network (D2NN), and demonstrate the robust sorting of 120 Laguerre–Gaussian (LG) modes experimentally in the visible spectrum. Our proposed beam sorter underscores the considerable potential of D2NN in optical field manipulation and promises to enhance the diverse applications of vector vortex beams.

Influence of High-Order Twisting Phases on Polarization States and Optical Angular Momentum of a Vector Light Field

This study investigates the influence of high-order twisting phases on polarization states and optical angular momentum of a vector light field with locally linear polarization and a hybrid state of polarization (SoP). The twisted vector optical field (TVOF) is experimentally generated based on the orthogonal polarization bases with high-order twisting phases. The initial SoP of a TVOF modulated by the high-order twisting phase possesses various symmetric distributions. The propagation properties of a high-order TVOF with locally linear polarization and hybrid SoP are explored, including the intensity compression, expansion, and conversion between the linear and circular polarization components. In particular, orbital angular momentum (OAM) appears in a high-order TVOF during propagation where no OAM exists in the initial field. The variation of OAM distribution in cross-section becomes more frequent with the increase of the twisting phase order. In addition, a non-symmetric OAM distribution appears in a non-isotropic TVOF, leading to the rotation of the beam around the propagation axis during propagation. The optical energy flow distribution of a high-order TVOF provides a more profound understanding of the propagation dynamics of high-order TVOF. These results provide a new approach for optical field manipulation in a high-order TVOF.

Design Strategies and Applications of Dimensional Optical Field Manipulation Based on Metasurfaces.

Recent rapid progress in metasurfaces is underpinned by the physics of local and nonlocal resonances and the modes coupling among them, leading to tremendous applications such as optical switching, information transmission, and sensing. In this review paper, we provide an overview of the recent advances in a broad range of dimensional optical field manipulation based on metasurfaces categorized into different classes based on design strategies. We start from the near-field optical resonances of artificial nanostructures and discuss the far-field optical wave manipulation based on fundamental mechanisms such as mode generation and mode coupling. We summarize the recent advances in optical field manipulation based on metasurfaces in different optical dimensions such as phase and polarization and discuss newly-developed dimensions, such as the orbital angular momentum and the coherence dimensions resulting from phase modulation. Then, we review the recent achievements of multiplexing and multifunctional metasurfaces empowered by multidimensional optical field manipulation for optical information transmission and integrated applications. Finally, we conclude with a few perspectives on emerging trends, possible directions, and existing challenges in this fast-developing field. This article is protected by copyright. All rights reserved.

Spatial and frequency-selective optical field coupling absorption in an ultra-thin random metasurface.

Simplified thin-film structures with the capability of spatial and frequency-selective optical field coupling and absorption are desirable for nanophotonics. Herein, we demonstrate the configuration of a 200-nm-thick random metasurface formed by refractory metal nanoresonators, showing near-unity absorption (absorptivity > 90%) covering the visible and near-infrared range (0.380-1.167 µm). Importantly, the resonant optical field is observed to be concentrated in different spatial areas according to different frequencies, paving a feasible way to artificially manipulate spatial coupling and optical absorption via the spectral frequency. The methods and conclusions derived in this work are applicable throughout a wide energy range and hold applications for frequency-selective nanoscale optical field manipulation.

Optical force exerted on the two dimensional transition-metal dichalcogenide coated dielectric particle by Gaussian beam

Two-dimensional transition-metal dichalcogenide (TMDC) exhibits a series of distinctive optical and electrical characteristics, which make it has a good application prospect in the field of optical manipulation. Based on the Mie theory, we investigate the radiation force exerted on the TMDC wrapped dielectric particle by Gaussian wave. Theoretical calculations show that the optical force spectra exhibit two resonant peaks in the visible region, which are generated by the interband exciton transitions in TMDC. Magnitude and morphology of the excitonic peaks could be modulated effectively by tuning the number of coated TMDC layers. Furthermore, the excitonic peaks transform significantly with particle size due to the variation of coupling strength between the dielectric particle and TMDC coating. The investigation provides potential applications in optical manipulations and light-matter interactions.

Dispersion‐Enabled Symmetry Switching of Photonic Angular‐Momentum Coupling

AbstractPhotonic spin‐orbit interactions describe the interactions between spin angular momentum and orbital angular momentum of photons, which play essential roles in subwavelength optics. However, the influence of frequency dispersion on photonic angular‐momentum coupling is rarely studied. Here, by elaborately designing the contribution of the geometric phase and waveguide propagation phase, the dispersion‐enabled symmetry switching of photonic angular‐momentum coupling is experimentally demonstrated. This notion may induce many exotic phenomena and be found in enormous applications, such as the spin‐Hall effect, optical calculation, and wavelength division multiplexing systems. As a proof‐of‐concept demonstration, two metadevices, a multi‐channel vectorial vortex beam generator and a phase‐only hologram, are applied to experimentally display optical double convolution, which may offer additional degrees of freedom to accelerate computing and a miniaturization configuration for optical convolution without collimation operation. These results may provide a new opportunity for complex vector optical field manipulation and calculation, optical information coding, light‐matter interaction manipulation, and optical communication.

Multiscale Optical Field Manipulation via Planar Digital Optics

Replacing curved and bulky optical elements with thin and lightweight counterparts is a persistent pursuit of the optical society. Metasurfaces, as two-dimensional artificial metamaterials, have attracted much attention because of their exceptional ability to manipulate electromagnetic waves such as amplitude, phase, polarization, propagation direction, and so on. With the great advances in planar digital optics and vector optical field manipulation via metasurfaces, planar optics with multiscale optical field manipulation from subwavelength meta-atoms (tens of nanometers) to large-scale planar devices (hundreds of millimeters) is highly desired in practical applications, which may replace conventional optical devices with superior performance and decreased weight or even create completely new functionalities. Here, we give a perspective on the multiscale optical field manipulation based on planar optics. Particular emphasis is given to multifunctional optical field manipulation, intelligent design, and mass fabrication, as well as their potential applications in lightweight laser systems, diffractive sails, integrated optics, etc.

Pixel level control of amplitude, phase, and polarization of an arbitrary vector beam

The generation of vector beams with complex spatial distributions is significant in the field of optical manipulation, optical metrology, optical microscopy, and so on. In this work, we propose a method to generate arbitrary vector beams, which is based on the complex amplitude beam shaping technology and the interferometric optical path configuration. With the method, we can achieve pixel-level control of amplitude, phase, and polarization of an arbitrary vector beam. Furthermore, different polarization states and orientations can be designed to coexist in one beam. The method has been verified with theoretical analysis and experimental results. The proposed method expands the application range of vector beams and provides a conducive way to explore the optical properties of the vector beams.

Four-vector optical Dirac equation and spin-orbit interaction of structured light

The spin-orbit interaction of light is a crucial concept for understanding the electromagnetic properties of a material and realizing the spin-controlled manipulation of optical fields. Achieving these goals requires a complete description of spin-dependent optical phenomena in the context of vector-wave mechanics. We develop an extended Dirac theory for optical fields in generic media, which was found to be akin to a non-Hermitian chiral extension of massive fermions with anomalous magnetic momenta moving in an external pseudomagnetic field. This similarity allows us to investigate the optical behaviors of a material by effective field-theory methods and can find wide applications in metamaterials, photonic topological insulators, etc. We demonstrate this method by studying the spin-orbit interaction of structured light in a spin-degenerate medium and inhomogeneous isotropic medium, which leads to both spin-orbital Hall effects and spin-to-orbital angular momentum conversion. Of importance, our approach provides simple and clear physical insight into the spin-orbit interaction of light in generic media, and could potentially bridge our understanding of topological insulators between electronic and photonic systems.

Optical tractor beam for a cluster of plasmonic and dielectric and chiral Mie objects

A light beam pushes any object towards the direction of its propagation as light or quantum of light, photon, carries momentum. However, a light beam can also pull a particle backward towards the source — regarded as an optical tractor beam. Despite a series of phenomenal works being done in the field of optical manipulation using optical tractor beams, optical setup that can enable the optical pulling of all objects (i.e., dielectric, plasmonic and chiral) is still extremely rare. This work stands as the very first proposal of a simple and generic all-optical setup, where attaining optical tractor beam effect over all objects within a cluster is facilitated. Such optical pulling effect is observed only over a dielectric substrate (but not over plasmonic substrate) when two simple plane waves superimpose appropriately maintaining certain conditions. The emergence of such counterintuitive force has been explained based on distinct physical phenomena. For instance, in case of the dielectric and chiral nanoparticles, origin of the pulling force has been explained based on the field induced multipole radiation; whereas, in case of the plasmonic scatterer, the pulling has been explained based on the reversal of induced current density within the object.

Realization of maximum optical intrinsic chirality with bilayer polyatomic metasurfaces.

Optical chirality plays a key role in optical biosensing and spin-selective optical field manipulation. However, the maximum optical intrinsic chirality, which is represented by near-unity circular dichroism (CD), is yet to be achieved in a wide bandwidth range based on nanostructures. Here, we utilize dielectric bilayer polyatomic metasurfaces to realize the maximum optical intrinsic chirality over a wide bandwidth range. The CD efficiency of the two designed metasurfaces with opposite chirality is 99.9% at 1350 nm and over 98% from 1340 nm to 1361 nm. Our work provides a straightforward and powerful method for the realization of maximum optical intrinsic chirality, which has great potential in spin-selective optical wave manipulation.

Optically reconfigurable higher-order valley photonic crystals based on enhanced Kerr effect.

The reconfigurable higher-order topological states are realized in valley photonic crystals with enhanced optical Kerr nonlinearity. The inversion symmetry of the designed valley photonic crystal is broken due to the difference in optical responses between adjacent elements rather than their geometry structures. Therefore, by constructing photonic crystals with distinct topological phases, valley-dependent topological states can be realized, and their reconfigurability is demonstrated based on the Kerr effect. The investigated higher-order topological photonic crystals exhibit great robustness against the structural defects and inferior quality of pump introduced around the corner. Our work provides a new, to the best of our knowledge, platform for studying optical field manipulation and optical devices fabrication in the context of nonlinear higher-order topology.

Flexible Confinement and Manipulation of Mie Resonances via Nano Rectangular Hollow Metasurfaces

AbstractMie resonances excited in high‐index all‐dielectric metasurfaces provide a powerful platform for the constraint and manipulation of light at the subwavelength scale, which enable tremendous advanced developments in optical field manipulation, imaging, and sensing. Recently, how to manipulate and confine Mie resonances in the frequency domain has attracted tremendous interest since it is invaluable for the implementation of frequency‐selective and ‐multiplexed optical devices. Here, the authors theoretically analyze and experimentally demonstrate that the nano rectangular hollow (NRH) metasurfaces are promising candidates for the flexible confinement and effective manipulation of Mie resonances in the frequency domain. They reveal that the diameter of the hollow in the NRH can provide an efficient degree of freedom for the constraint of displace currents in the space domain, which results in the confinement of Mie resonances in the frequency domain. The excitation wavelength of the Mie resonance can also be manipulated by adjusting the side length of the NRH. The potential uses of NRH metasurfaces in the implementation of frequency‐selective intensity encoding and optical encryption are theoretically and experimentally demonstrated. The results provide a fertile ground for confining Mie resonances in the frequency domain and can be further applied in frequency‐multiplexed optical devices.

Recent advances in ultrafast plasmonics: from strong field physics to ultraprecision spectroscopy

Abstract Surface plasmons, the collective oscillation of electrons, enable the manipulation of optical fields with unprecedented spatial and time resolutions. They are the workhorse of a large set of applications, such as chemical/biological sensors or Raman scattering spectroscopy, to name only a few. In particular, the ultrafast optical response configures one of the most fundamental characteristics of surface plasmons. Thus, the rich physics about photon–electron interactions could be retrieved and studied in detail. The associated plasmon-enhanced electric fields, generated by focusing the surface plasmons far beyond the diffraction limit, allow reaching the strong field regime with relatively low input laser intensities. This is in clear contrast to conventional optical methods, where their intrinsic limitations demand the use of large and costly laser amplifiers, to attain high electric fields, able to manipulate the electron dynamics in the non-linear regime. Moreover, the coherent plasmonic field excited by the optical field inherits an ultrahigh precision that could be properly exploited in, for instance, ultraprecision spectroscopy. In this review, we summarize the research achievements and developments in ultrafast plasmonics over the last decade. We particularly emphasize the strong-field physics aspects and the ultraprecision spectroscopy using optical frequency combs.

High-Precision Calibration of Phase-Only Spatial Light Modulators

In the fields of optics and photonics, phase-only spatial light modulators (SLMs) play an increasingly important role in wave-front engineering. However, the SLMs are subject to wavefront distortion arising from the imperfection in the birefringence effect and physical structure of modulators. This paper presents a simple self-interference phase calibration method applicable to liquid-crystal SLM. We build an interferometric imaging system based on the Pancharatnam phase-shifting to measure the phase distribution of a light beam coming from SLMs. Two types of phase modulation errors of SLMs can be characterized in the measurement process: the erroneous gamma curve and shape aberration. The former belongs to dynamic phase distortion and is measured through a four-step Pancharatnam phase-shifting interference, which allows a one-shot recording of interference pattern via a polarization camera; the latter represents static phase distortion and is extracted from the interference between light waves coming from different regions of the SLM panel by using Zernike polynomial fitting. Our method has the advantages of high-precision pixel-wise phase correction and robustness against environmental disturbance and thus can facilitate the applications of SLM in optical field manipulation.