scholarly journals Orbital angular momentum multiplication in plasmonic vortex cavities

2021 ◽  
Vol 7 (33) ◽  
pp. eabg5571
Author(s):  
Grisha Spektor ◽  
Eva Prinz ◽  
Michael Hartelt ◽  
Anna-Katharina Mahro ◽  
Martin Aeschlimann ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Vortex Lattice ◽  
Degree Of Freedom ◽  
Time Resolved ◽  
Pump Probe ◽  
Core Feature ◽  
Potential Applications ◽  
And Control ◽  
Photoemission Electron

Orbital angular momentum of light is a core feature in photonics. Its confinement to surfaces using plasmonics has unlocked many phenomena and potential applications. Here, we introduce the reflection from structural boundaries as a new degree of freedom to generate and control plasmonic orbital angular momentum. We experimentally demonstrate plasmonic vortex cavities, generating a succession of vortex pulses with increasing topological charge as a function of time. We track the spatiotemporal dynamics of these angularly decelerating plasmon pulse train within the cavities for over 300 femtoseconds using time-resolved photoemission electron microscopy, showing that the angular momentum grows by multiples of the chiral order of the cavity. The introduction of this degree of freedom to tame orbital angular momentum delivered by plasmonic vortices could miniaturize pump probe–like quantum initialization schemes, increase the torque exerted by plasmonic tweezers, and potentially achieve vortex lattice cavities with dynamically evolving topology.

scholarly journals Optical vortex lattice: an exploitation of orbital angular momentum

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Liuhao Zhu ◽  
Miaomiao Tang ◽  
Hehe Li ◽  
Yuping Tai ◽  
Xinzhong Li
Keyword(s):  
Angular Momentum ◽  
Optical Tweezers ◽  
Orbital Angular Momentum ◽  
Vortex Lattice ◽  
Optical Vortex ◽  
Yeast Cells ◽  
Particle Manipulation ◽  
Complex Motion ◽  
Potential Applications ◽  
Vortex Beams

Abstract Generally, an optical vortex lattice (OVL) is generated via the superposition of two specific vortex beams. Thus far, OVL has been successfully employed to trap atoms via the dark cores. The topological charge (TC) on each optical vortex (OV) in the lattice is only ±1. Consequently, the orbital angular momentum (OAM) on the lattice is ignored. To expand the potential applications, it is necessary to rediscover and exploit OAM. Here we propose a novel high-order OVL (HO-OVL) that combines the phase multiplication and the arbitrary mode-controllable techniques. TC on each OV in the lattice is up to 51, which generates sufficient OAM to manipulate microparticles. Thereafter, the entire lattice can be modulated to desirable arbitrary modes. Finally, yeast cells are trapped and rotated by the proposed HO-OVL. To the best of our knowledge, this is the first realization of the complex motion of microparticles via OVL. Thus, this work successfully exploits OAM on OVL, thereby revealing potential applications in particle manipulation and optical tweezers.

On-chip discrimination of orbital angular momentum of light with plasmonic nanoslits

Nanoscale ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 2227-2233 ◽  
Author(s):  
Shengtao Mei ◽  
Kun Huang ◽  
Hong Liu ◽  
Fei Qin ◽  
Muhammad Q. Mehmood ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Optical Communication ◽  
Communication System ◽  
Degree Of Freedom ◽  
System Capacity ◽  
Optical Communication System ◽  
On Chip

The orbital angular momentum (OAM) of light can be taken as an independent and orthogonal degree of freedom for multiplexing in an optical communication system, potentially improving the system capacity to hundreds of Tbits per second.

scholarly journals Selective time-dependent changes of Cu(DPPE)(DMP)·PF6on photoexcitation

2014 ◽  
Vol 70 (a1) ◽  
pp. C776-C776 ◽  
Author(s):  
Elzbieta Trzop ◽  
Bertrand Fournier ◽  
Katarzyna Jarzembska ◽  
Jesse Sokolow ◽  
Radoslaw Kaminski ◽  
...  
Keyword(s):  
Structural Changes ◽  
Dye Sensitized Solar Cells ◽  
Department Of Energy ◽  
Data Sets ◽  
Monoclinic System ◽  
Time Resolved ◽  
Pump Probe ◽  
Light Emitting Devices ◽  
Potential Applications ◽  
Photon Source

Thanks to their potential applications as light-emitting devices, chemical sensors and dye-sensitized solar cells, heteroleptic copper (I) complexes have been extensively studied. Cu(DPPE)(DMP)·PF6(dppe= 1,2-bis(diphenylphosphino)ethane; dmp = 2,9-dimethyl-1,10-phenanthroline) crystallizes in the monoclinic system, P21/c, with two independent molecules in the asymmetric unit. Previous studies on this system [1,2] show strong temperature-dependent emission. The complex was studied at 90K under 355nm laser excitation. At this temperature, the luminescence decay for Cu(DPPE)(DMP)·PF6is biexponential with lifetimes of ~3μs and ~28μs. Two time-resolved X-ray diffraction techniques were applied for studies: (1) a Laue technique at BioCARS ID-14 beamline at the Advanced Photon Source, and (2) monochromatic diffraction at a newly constructed in-house pump-probe monochromatic facility at the University at Buffalo. Structural changes determined with the two methods are in qualitative agreement; discrepancies in position of the Cu and P atoms were observed. The molecular distortions were smaller than those determined at 16K in the earlier synchrotron study by Vorontsov et al. [2]. Photodeformation maps (see Figure below), in which the increase in temperature on photoexcitation has been eliminated, clearly illustrate the photoinduced atomic shifts for both data sets. Results will be compared with those obtained for other studied heteroleptic copper (I) complexes, for instance Cu[(1,10-phenanthroline-N,N′) bis(triphenylphosphine)]·BF4[3]. The in-house pump-probe facility is discussed by Radoslaw Kaminski at this meeting. Research funded by the National Science Foundation (CHE1213223). BioCARS Sector 14 at APS is supported by NIH (RR007707). The Advanced Photon Source is funded by the Office of Basic Energy Sciences, U.S. Department of Energy, (W-31-109-ENG-38). KNJ is supported by the Polish Ministry of Science and Higher Education through the "Mobility Plus" program.

scholarly journals Continuous Variable Entanglement in Non-Zero Orbital Angular Momentum States

Proceedings ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Adriana Pecoraro ◽  
Filippo Cardano ◽  
Lorenzo Marrucci ◽  
Alberto Porzio
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Direct Detection ◽  
Hybrid Approach ◽  
Photon Number ◽  
Local Oscillator ◽  
Continuous Variable ◽  
Degree Of Freedom ◽  
Entangled State ◽  
Continuous Variables

Orbital angular momentum is a discrete degree of freedom that can access an infinite dimensional Hilbert space, thus enhancing the information capacity of a single optical beam. Continuous variables field quadratures allow achieving some quantum tasks in a more advantageous way with respect to the use of photon-number states. Here, we use a hybrid approach realizing bipartite continuous-variable Gaussian entangled state made up of two electromagnetic modes carrying orbital angular momentum. A q-plate is used for endowing a pair of entangled beams with such a degree of freedom. This quantum state is then completely characterized thanks to a novel design of a homodyne detector in which also the local oscillator is an orbital angular momentum-carrying beams so allowing the direct detection of vortex modes quadratures.

Time-resolved orbital angular momentum spectroscopy

2015 ◽  
Vol 107 (3) ◽  
pp. 032406 ◽  
Author(s):  
Mehmet A. Noyan ◽  
James M. Kikkawa
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Time Resolved

Femtosecond Magnetism When the Orbital Angular Momentum is Quenched

SPIN ◽  
2015 ◽  
Vol 05 (04) ◽  
pp. 1540009 ◽  
Author(s):  
M. S. Si ◽  
D. Z. Yang ◽  
D. S. Xue ◽  
G. P. Zhang
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Magnetic Circular Dichroism ◽  
Optical Excitation ◽  
Spin Moment ◽  
Spin Orbit Coupling ◽  
Level System ◽  
Orbital Moment ◽  
Time Resolved ◽  
X Ray

In femtosecond magnetism, a femtosecond laser pulse affects the spin moment only indirectly through the orbital angular momentum and the spin–orbit coupling. A long-standing puzzle is what happens if the orbital angular momentum itself is quenched. Here, we employ a four-level system to resolve this puzzle. The results show that the quenching of the orbital angular moment in the ground state has no direct relation to the spin moment change. By contrast, the orbital moment can be restored partially after the pulsed optical excitation and can affect the demagnetization. Importantly, this study confirms that the orbital moment indeed responds to the laser field faster than spin if the pulse duration is short, consistent with the recent time-resolved X-ray magnetic circular dichroism experiment. Therefore, our finding shines new light on femtosecond magnetism.

scholarly journals A Review of Tunable Orbital Angular Momentum Modes in Fiber: Principle and Generation

2019 ◽  
Vol 9 (12) ◽  
pp. 2408 ◽  
Author(s):  
Lipeng Feng ◽  
Yan Li ◽  
Sihan Wu ◽  
Wei Li ◽  
Jifang Qiu ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Rotation Speed ◽  
Degree Of Freedom ◽  
Particle Rotation ◽  
Large Capacity ◽  
Linearly Polarized ◽  
Basic Concepts ◽  
Polarization States ◽  
Linearly Polarized Modes

Orbital angular momentum (OAM) beams, a new fundamental degree of freedom, have excited a great diversity of interest due to a variety of emerging applications. The scalability of OAM has always been a topic of discussion because it plays an important role in many applications, such as expanding to large capacity and adjusting the trapped particle rotation speed. Thus, the generation of arbitrary tunable OAM mode has been paid increasing attention. In this paper, the basic concepts of classical OAM modes are introduced firstly. Then, the tunable OAM modes are categorized into three types according to the orbital angular momentums and polarization states of mode carrying. In order to understand the OAM evolution of a mode intuitively, three kinds of Poincaré spheres (PSs) are introduced to represent the three kinds of tunable OAM modes. Numerous methods generating tunable OAM modes can be roughly divided into two types: spatial and fiber-based generation methods. The principles of fiber-based generation methods are interpreted by introducing two mode bases (linearly-polarized modes and vector modes) of the fiber. Finally, the strengths and weaknesses of each generation method are pointed out and the key challenges for tunable OAM modes are discussed.

scholarly journals Controlling Conical Beam Carrying Orbital Angular Momentum with Transmissive Metasurface

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jun Sun ◽  
Ke Chen ◽  
Kai Qu ◽  
Junming Zhao ◽  
Tian Jiang ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
High Speed ◽  
Design Method ◽  
Cone Angle ◽  
Full Control ◽  
Potential Applications ◽  
Conical Radiation ◽  
Conical Beam ◽  
Good Agreement

Conical beams have potential uses in wireless and satellite-based communication. In this study, we propose a method using a transmissive metasurface to achieve full control of the diverging effect of orbital angular momentum (OAM) modes to form the desired conical beam. A patch antenna functioning as the feed source is combined with the transmissive metasurface to enable the integration of the source and metasurface. For full control of conical radiation, including the cone angle and OAM mode, we introduce both radial and circumferential phase gradients to the proposed metasurface. Experiments are conducted in the microwave region to validate the design method, which shows good agreement with the simulation results. The proposed metasurface provides a means of flexibly generating conical beams with the designed OAM mode to assist potential applications in high-speed wireless communication.

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