scholarly journals Long-distance optical pulling of nanoparticle in a low index cavity using a single plane wave

2020 ◽  
Vol 6 (21) ◽  
pp. eaaz3646 ◽  
Author(s):  
E. Lee ◽  
T. Luo
Keyword(s):  
Plane Wave ◽  
Incident Light ◽  
Propagation Direction ◽  
Core Shell ◽  
Long Distance ◽  
Single Plane ◽  
Practical Applications ◽  
Multipole Analysis ◽  
Cavity Structure ◽  
Pulling Force

Optical pulling force (OPF) can make a nanoparticle (NP) move against the propagation direction of the incident light. Long-distance optical pulling is highly desired for nano-object manipulation, but its realization remains challenging. We propose an NP-in-cavity structure that can be pulled by a single plane wave to travel long distances when the spherical cavity wrapping the NP has a refractive index lower than the medium. An electromagnetic multipole analysis shows that NPs made of many common materials can receive the OPF inside a lower index cavity. Using a silica-Au core-shell NP that is encapsulated by a plasmonic nanobubble, we experimentally demonstrate that a single laser can pull the Au NP-in-nanobubble structure for ~0.1 mm. These results may lead to practical applications that can use the optical pulling of NP, such as optically driven nanostructure assembly and nanoswimmers.

scholarly journals Core-Shell Nano-Antenna Configurations for Array Formation with More Stability Having Conventional and Non-Conventional Directivity and Propagation Behavior

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
Qaisar Hayat ◽  
Junping Geng ◽  
Xianling Liang ◽  
Ronghong Jin ◽  
Sami Ur Rehman ◽  
...  
Keyword(s):  
Plane Wave ◽  
Propagation Direction ◽  
Core Shell ◽  
Incident Plane Wave ◽  
Polarization Direction ◽  
Shell Nanoparticles ◽  
Incident Plane ◽  
Core Shell Nanoparticles ◽  
Coated Nanoparticle ◽  
2D Array

The enhancement of optical characteristics at optical frequencies deviates with the choice of the arrangement of core-shell nanoparticles and their environment. Likewise, the arrangements of core-shell nanoparticles in the air over a substrate or in liquid solution makes them unstable in the atmosphere. This article suggests designing a configuration of an active spherical coated nanoparticle antenna and its extended array in the presence of a passive dielectric, which is proposed to be extendable to construct larger arrays. The issue of instability in the core-shell nanoantenna array models is solved here by inserting the passive dielectric. In addition to this, the inclusion of a dielectric in the array model reports a different directivity behaviour than the conventional array models. We found at first that the combination model of the active coated nanoparticle and passive sphere at the resonant frequency can excite a stronger field with a rotated polarization direction and a propagation direction different from the incident plane-wave. Furthermore, the extended 2D array also rotates the polarization direction and propagation direction for the vertical incident plane-wave. The radiation beam operates strong multipoles in the 2D array plane at resonant frequency (behaving non-conventionally). Nevertheless, it forms a clear main beam in the incident direction when it deviates from the resonance frequency (behaving conventionally). The proposed array model may have possible applications in nano-amplifiers, nano-sensors and other integrated optics.

Improving Image Quality of Single Plane Wave Ultrasound via Deep Learning Based Channel Compounding

2020 ◽  
Author(s):  
Sven Rothlubbers ◽  
Hannah Strohm ◽  
Klaus Eickel ◽  
Jurgen Jenne ◽  
Vincent Kuhlen ◽  
...  
Keyword(s):  
Deep Learning ◽  
Image Quality ◽  
Plane Wave ◽  
Single Plane

scholarly journals Plasmonic linear nanomotor using lateral optical forces

2020 ◽  
Vol 6 (45) ◽  
pp. eabc3726
Author(s):  
Yoshito Y. Tanaka ◽  
Pablo Albella ◽  
Mohsen Rahmani ◽  
Vincenzo Giannini ◽  
Stefan A. Maier ◽  
...  
Keyword(s):  
Laser Beam ◽  
Incident Light ◽  
Lateral Force ◽  
Diffraction Limit ◽  
Propagation Direction ◽  
Optical Force ◽  
Optical Forces ◽  
Incident Laser ◽  
New Class ◽  
Force Direction

Optical force is a powerful tool to actuate micromachines. Conventional approaches often require focusing and steering an incident laser beam, resulting in a bottleneck for the integration of the optically actuated machines. Here, we propose a linear nanomotor based on a plasmonic particle that generates, even when illuminated with a plane wave, a lateral optical force due to its directional side scattering. This force direction is determined by the orientation of the nanoparticle rather than a field gradient or propagation direction of the incident light. We demonstrate the arrangements of the particles allow controlling the lateral force distributions with the resolution beyond the diffraction limit, which can produce movements, as designed, of microobjects in which they are embedded without shaping and steering the laser beam. Our nanomotor to engineer the experienced force can open the door to a new class of micro/nanomechanical devices that can be entirely operated by light.

scholarly journals Packaged Droplet Microresonator for Thermal Sensing with High Sensitivity

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3881 ◽  
Author(s):  
Xiaogang Chen ◽  
Liang Fu ◽  
Qijing Lu ◽  
Xiang Wu ◽  
Shusen Xie
Keyword(s):  
Liquid Droplet ◽  
Thermal Sensitivity ◽  
High Sensitivity ◽  
Liquid Limit ◽  
Practical Applications ◽  
Sensing Applications ◽  
Cavity Structure ◽  
Thermal Sensing ◽  
Facile Fabrication ◽  
Definition Of

Liquid droplet and quasi-droplet whispering gallery mode (WGM) microcavities have been widely studied recently for the enhanced spatial overlap between the liquid and WGM field, especially in sensing applications. However, the fragile cavity structure and the evaporation of liquid limit its practical applications. Here, stable, packaged, quasi-droplet and droplet microcavities are proposed and fabricated for thermal sensing with high sensitivity. The sensitivity and electromagnetic field intensity distribution are analyzed by Mie theory, and a quantified definition of the quasi-droplet is presented for the first time to the best of our knowledge. By doping dye material directly into the liquid, lasing packaged droplet and quasi-droplet microcavity sensors with a high thermal sensitivity of up to 205.3 pm/°C are experimentally demonstrated. The high sensitivity, facile fabrication, and mechanically robust properties of the optofluidic, packaged droplet microresonator make it a promising candidate for future integrated photonic devices.

scholarly journals Enhanced Photo–Fenton Removal Efficiency with Core-Shell Magnetic Resin Catalyst for Textile Dyeing Wastewater Treatment

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 968
Author(s):  
Jie Zhong ◽  
Bin Yang ◽  
Yong Feng ◽  
Yang Chen ◽  
Li-Gao Wang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
In Situ Polymerization ◽  
Matrix Effects ◽  
Core Shell ◽  
Dyeing Wastewater ◽  
Practical Applications ◽  
Textile Dyeing ◽  
Reactive Radicals ◽  
Fenton System ◽  
Textile Dyeing Wastewater

Heterogeneous photo–Fenton reactions have been regarded as important technologies for the treatment of textile dyeing wastewaters. In this work, an efficient core-shell magnetic anion exchange resin (MAER) was prepared through in situ polymerization and used to remove reactive brilliant red (X-3B) in a UV–Fenton system. The MAER exhibited satisfactory removal efficiency for X-3B because of its highly effective catalytic activity. More than 99% of the X-3B (50 mg/L) was removed within 20 min in the UV–Fenton reaction. This is because the uniformly dispersed core-shell magnetic microsphere resin could suppress the aggregation of Fe3O4 nanoparticles and, thus, enhance the exposure of Fe reaction sites for catalytic reaction with H2O2. The good adsorption capacity of MAER also played an important role in promoting contact between X-3B and reactive radicals during the reaction. Mechanism research showed that hydroxyl radical (•OH) was the main reactive radicals for the removal of X-3B in the MAER UV–Fenton system. The MAER can be easily separated by a magnet after catalytic reactions. Moreover, the matrix effects of different substrates (Cl−, NO3−, SO42−, and humic acid) were investigated. The results showed that SO42− could be beneficial to improve the removal of X-3B but that the others decrease the removal. The MAER UV–Fenton also removed significant amounts of total organic carbon (TOC) for the X-3B solution and an actual textile dyeing industrial wastewater. The heterogeneous oxidation system established in this work may suggest prospects for practical applications in the treatment of textile dyeing wastewater.

scholarly journals Optical Pulling Using Chiral Metalens as a Photonic Probe

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3376
Author(s):  
Miao Peng ◽  
Hui Luo ◽  
Zhaojian Zhang ◽  
Tengfang Kuang ◽  
Dingbo Chen ◽  
...  
Keyword(s):  
Incident Light ◽  
Longitudinal Optical ◽  
Optical Force ◽  
Optical Manipulation ◽  
Maximum Value ◽  
Broadband Spectrum ◽  
Course Control ◽  
Pulling Forces ◽  
Potential Applications ◽  
Pulling Force

Optical pulling forces, which can pull objects in the source direction, have emerged as an intensively explored field in recent years. Conventionally, optical pulling forces exerted on objects can be achieved by tailoring the properties of an electromagnetic field, the surrounding environment, or the particles themselves. Recently, the idea of applying conventional lenses or prisms as photonic probes has been proposed to realize an optical pulling force. However, their sizes are far beyond the scope of optical manipulation. Here, we design a chiral metalens as the photonic probe to generate a robust optical pulling force. The induced pulling force exerted on the metalens, characterized by a broadband spectrum over 0.6 μm (from 1.517 to 2.117 μm) bandwidth, reached a maximum value of −83.76 pN/W. Moreover, under the illumination of incident light with different circular polarization states, the longitudinal optical force acting on the metalens showed a circular dichroism response. This means that the longitudinal optical force can be flexibly tuned from a pulling force to a pushing force by controlling the polarization of the incident light. This work could pave the way for a new advanced optical manipulation technique, with potential applications ranging from contactless wafer-scale fabrication to cell assembly and even course control for spacecraft.

scholarly journals Integrated Dual-DFB PIC for High-Purity THz Carrier Generation Enabling Ultrafast THz Wireless Communications

2021 ◽  
Author(s):  
Shi Jia ◽  
Mu-Chieh Lo ◽  
Lu Zhang ◽  
Oskars Ozolins ◽  
Aleksejs Udalcovs ◽  
...  
Keyword(s):  
Wireless Communications ◽  
Integrated Circuits ◽  
High Purity ◽  
High Speed ◽  
Single Channel ◽  
Cost Effective ◽  
Long Distance ◽  
Practical Applications ◽  
Integrated Cost ◽  
Thz Power

Abstract With the explosive growth of global wireless data traffic, the Terahertz band (0.3–10 THz) is promising for ultrafast wireless communications, due to the enormous available bandwidth [1]. Photonic generation of THz carriers displays extremely large tunable range and modulation bandwidth, making it nearly ideal for THz communications. However, the current photonics-based THz carrier generators are based on discrete bulky components [2] with high cost and energy consumption, which hinder them from practical applications. Here, we present an injection-locked heterodyne source based on generic foundry-fabricated photonic integrated circuits (PIC) attached to a photo-mixing uni-travelling carrier photodiode (UTC-PD), generating high-purity THz carriers for high-speed and long-distance wireless communication. The generated THz carrier can span from 0 to 1.4 THz, determined by the tunable wavelength spacing between the two distributed feedback (DFB) modes within the range 0-10.7 nm. We show that a generated 0.4 THz carrier transmits a record-high single-channel net rate of 131 Gbit/s over 10.7 m of wireless distance with only − 24 dBm emitted THz power, by employing 16-QAM-OFDM modulation and a nonlinear equalization technique. To the best of our knowledge, this is the highest data rate for a single-channel THz wireless transmission and requires the lowest THz power/bitrate/distance. The scheme of the monolithic dual-DFB PIC based THz generation shows a great potential for fully integrated, cost-effective and energy-efficient THz transmitters.

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