China
Africa
Explore chapters and articles related to this topic
Plasmonic Materials and Their Applications
Published in Song Sun, Wei Tan, Su-Huai Wei, Emergent Micro- and Nanomaterials for Optical, Infrared, and Terahertz Applications, 2023
Jinfeng Zhu, Yinong Xie, Yuan Gao
In past decades, photonic crystal with well-defined periodic structure is invented to tailor the electromagnetic wave propagation by creating an artificial band structure in the desired frequency range [113]. Plasmon-based metamaterials and metasurfaces share the same concept of photonic crystal, exploiting periodic lattice of metallic nanostructures to control the properties of electromagnetic wave. The major difference between plasmonic structure and photonic crystal is that subwavelength unit cells and periodicities are used in plasmonic technologies due to the strong optical confinement of surface plasmon, whereas unit cell sizes and periodicities on the wavelength scale are employed for the photonic crystal. As a result, the notorious diffraction limit is naturally overcome in the plasmonic metamaterial and metasurface, which is of paramount importance for high-resolution imaging and spectroscopy. In addition, the ability of plasmonic micro-nanostructures to confine and enhance the light field makes it useful in refractive index (RI) sensing, biosensing, surface-enhanced IR spectroscopy (SEIRS), SERS, nonlinear enhancement, absorbers, and many other fields, which will be briefly reviewed in this section.
Asymmetric Split-H Based Metasurfaces for Identification of Organic Molecules
Published in Pankaj K. Choudhury, Metamaterials, 2021
Ili F. Mohamad Ali, Ifeoma G. Mbomson, Marc Sorel, Nigel P. Johnson, Caroline Gauchotte-Lindsay, Richard M. De La Rue
A plasmonic metamaterial is one that, through interaction with electromagnetic radiation, produces artificial optical properties based on surface plasmon effects. The resonant oscillation of free electron gas in metals formed by the interactions of incident light with dielectrics and metals, known as surface plasmon resonance, is currently being used widely for biosensor applications. Sensing applications benefit from the tunability features of plasmonic resonance produced in the many metamaterials used for various vibrational modes in the region of IR spectroscopy [1–8]. The term metasurface is now widely used for metamaterials that are created as metallic patterns on the surface of substrates via the lithographic processes that are typical of planar fabrication technology. There are many molecular vibrations that occur in the mid-IR spectral region [9].
*
Published in Chad A. Mirkin, Spherical Nucleic Acids, 2020
Matthew R. Jones, Kevin L. Kohlstedt, Matthew N. O’Brien, Jinsong Wu, George C. Schatz, Chad A. Mirkina
The physical properties of matter rely fundamentally on the symmetry of constituent building blocks. This is particularly true for structures that interact with light via the collective motion of their conduction electrons (i.e., plasmonic materials), where the observation of exotic optical effects, such as negative refraction and electromagnetically induced transparency, require the coupling of modes that are only present in systems with nontrivial broken symmetries. Lithography has been the predominant fabrication technique for constructing plasmonic metamaterials, as it can be used to form patterns of arbitrary complexity, including those with broken symmetry. Here, we show that low-symmetry, 1D plasmonic structures that would be challenging to make using traditional lithographic techniques can be assembled using DNA as a programmable surface ligand. We investigate the optical properties that arise as a result of systematic symmetry breaking and demonstrate the appearance of π-type coupled modes formed from both dipole and quadrupole nanoparticle sources. These results demonstrate the power of DNA assembly for generating unusual structures that exhibit both fundamentally insightful and technologically important optical properties.
Multipole resonances-mediated dual-band tunable circular dichroism via vanadium dioxide chiral metamaterials
Published in Waves in Random and Complex Media, 2023
Shi Li, Tian Sang, Chaoyu Yang, Chui Pian, Yueke Wang, Bolun Hu, Cheng Liu
As a typical artificial metamaterial, plasmonic metamaterial exhibits unique and special abilities related to electromagnetic wave control, including strong field localization in the vicinity of the surfaces, which can upgrade the intensity of light-matter interactions and can enhance the chiroptical responses [8–10]. Plasmonic chiral metamaterials have been shown to enable numerous optical applications via the design and tailoring of their subunit building blocks such as plasmonic chiral metamaterial absorbers [11], chiral optofluidics [12], chiral coding [13,14], and photodetection [15]. However, the functions of the traditional plasmonic chiral metamaterials are fixed once being fabricated [16–19], and dynamical controls of chiral responses for versatile applications such as switching or tuning functions are highly desired.
Tunable near-infrared epsilon-near-zero and plasmonic properties of Ag-ITO co-sputtered composite films
Published in Science and Technology of Advanced Materials, 2018
Chaonan Chen, Zhewei Wang, Ke Wu, Hui Ye
Alternative plasmonic materials to conventional noble metals have been the forefront of intense study during the last decades, since feasible devices based on metallic building elements are impeded by their inherent bottlenecks, such as dissipative ohmic losses, non-tunable optical properties, and incompatibility with standard nanofabrication processes [1–3]. The extensive researches about alternatives mainly include highly-doped metal oxides, transition-metal nitrides, and two-dimensional materials [4–6]. Owing to their capability to support surface plasmons in the infra-red region, experimental realizations of promising plasmonic metamaterials and devices have been enabled [7–10]. One of the key issues for high-performing plasmonic materials is that their optical parameters can be manipulated at ease. In particular, the near-zero optical index (e.g. epsilon-near-zero, ENZ) is of paramount significance to not only the tunability of plasmonic resonances, but also some unique features allowing unprecedented optical phenomena [11,12], for instance, giant optical nonlinearity at the ENZ region [13,14]. The capability for plasmonic nanostructures to confine optical energy in sub-λ volumes also enables them to gain high energy concentration and enhance the optical nonlinearity. So, the ability of activating either localized plasmonic behaviors or propagating surface plasmon polaritons (SPP) modes makes plasmonic materials attractive in the field of bio- and chemical sensing, on-chip all-optical devices, information processing, nonlinear optics or other areas requiring respond speed and high efficiency [15].
High-efficiency broadband polarisation converter via patterned multilayer twisted liquid crystal polymer
Published in Liquid Crystals, 2023
Shang Liu, Tibin Zeng, Jin Xie, Yingjie Zhou, Xiangyu Jiang, Xianglin Ye, Fan Fan, Shuangchun Wen
So far, 3M’s broadband reflective polariser has become the most used commercial product due to the significant improvement in the recycling efficiency of the display system achieved by reflection, and its outstanding performance in bandwidth and acceptance angle [12]. In recent years, benefiting from the advancement of nanofabrication technologies, ultra-thin optics represented by metasurfaces have gradually emerged [13–15]. Polarisation conversion could be achieved by designing specific periodic nanostructures with subwavelength unit. For instance, an ultra-high-efficiency linear polariser based upon an all-dielectric metamaterial patterned at subwavelength dimension has been proposed [14]. Additionally, a planar-helix chiral metamaterial is employed to expand bandwidth while maintaining high circular polarisation selection efficiency [15]. There are some factors such as limited size and high cost preventing the extensive use of plasmonic metamaterial and metasurface. Moreover, the performance of these polarisers may well degrade with a change in incident angle because exquisite nanostructures are only optimised for efficiency without considering possible oblique incidence. Juggling efficiency, bandwidth and incident angle all at the same time will inevitably bring greater challenges to design and fabrication of device structures, but LC may tackle these challenges well with the development of alignment technology. LC materials have been massively found in current optical components including the LC display and remote sensing applications due to its fascinating birefringent property and electrically dynamic optic-electric tunability [16–27]. For instance, taking advantage of LC retardation compensation, remarkable achromatic PG and retarders employing twisted structure have been reported [16–21], and the team has also proposed fantastic polarisation conversion systems, which manifests excellent performance in terms of efficiency, angle tolerance and bandwidth [24,25]. Besides, complex nanoscale-ordered LC polymer film is developed to realise holographic polariser, which demonstrates high transmittance but with a limited operating bandwidth [26]. Overall, planar LC optical devices with sophisticated structures have been endowed with prominent advantages in terms of manufacturing difficulty and weight, providing us a whole new perspective for designing the multifunctional integrated optical system.