A5038024555- Plasmonic and Surface Plasmon Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Photonic and Optical Devices
- 2D Materials and Applications
- Orbital Angular Momentum in Optics
- Spectroscopy and Quantum Chemical Studies
- Perovskite Materials and Applications
- Metamaterials and Metasurfaces Applications
- Strong Light-Matter Interactions
- Organic Light-Emitting Diodes Research
- Advanced Fiber Laser Technologies
- Luminescence and Fluorescent Materials
- Nanowire Synthesis and Applications
- Neural Networks and Reservoir Computing
- Modular Robots and Swarm Intelligence
- Advanced Thermodynamics and Statistical Mechanics
- melanin and skin pigmentation
- Graphene research and applications
- MXene and MAX Phase Materials
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Advanced Memory and Neural Computing
- Near-Field Optical Microscopy
- Biocrusts and Microbial Ecology
- Advanced biosensing and bioanalysis techniques
University of Glasgow
2023-2024
Indian Institute of Science Education and Research Pune
2017-2022
We report on the experimental observation of differential wavevector distribution surface-enhanced Raman scattering (SERS) and fluorescence from dye molecules confined to a gap between plasmonic silver nanowire thin, gold mirror. The was mainly higher values in-plane wavevectors, whereas SERS signal uniformly distributed along all wavevectors. optical energy-momentum spectra distal end revealed strong polarization dependence this differentiation. All these observations were corroborated by...
Abstract Understanding the function of a biomolecule hinges on its 3D conformation or secondary structure. Chirally sensitive, optically active techniques based differential absorption UV–vis circularly polarized light excel at rapid characterisation structures. However, Raman spectroscopy, powerful method for determining structure simple molecules, has limited capacity structural analysis biomolecules because intrinsically weak optical activity, necessitating millimolar (mM) sample...
Abstract Room‐temperature phosphorescence of metal and heavy atom‐free organic molecules has emerged as an area great potential in recent years. A rational design played a critical role controlling the molecular ordering to impart efficient intersystem crossing stabilize triplet state achieve room‐temperature ultralong phosphorescence. However, most cases, strategies strengthen efficiency have resulted reduced lifetime, available nearly degenerate singlet‐triplet energy levels natural...
Abstract Chiral nanophotonic platforms provide a means of creating near fields with both enhanced asymmetric properties and intensities. They can be exploited for optical measurements that allow enantiomeric discrimination at detection levels > 6 orders magnitude than is achieved conventional chirally sensitive spectroscopic methods based on circularly polarized light. Here it shown surface Raman spectroscopy (SERS) such local probe the field environment. It used to achieve chiral...
Light-activated colloidal assembly and swarming can act as model systems to explore non-equilibrium state of matter. In this context, creating new experimental platforms facilitate control two-dimensional crystals are contemporary interest. paper, we present an study silica microparticles in the vicinity a single-crystalline gold microplate evanescently excited by 532 nm laser beam. The acts source heat establishes thermal gradient system. created optothermal potential assembles colloids...
Chiral molecules, a cornerstone of chemical sciences with applications ranging from pharmaceuticals to molecular electronics, come in mirror-image pairs called enantiomers. However, their synthesis often requires complex control geometry. We propose strategy "electromagnetic enantiomers" for inducing chirality molecules located within engineered nanocavities using light, eliminating the need intricate design. This approach works by exploiting strong coupling between nonchiral molecule and...
We report on the generation, and momentum space distribution of fluorescence emission from individual SiO2 microsphere dye coated Au mirror. The molecular mediated via whispering gallery modes sphere is studied using polarization resolved optical energy-momentum micro-spectroscopy. Our experiments reveal intensity dependence split cavity as a function in-plane wavevector in far field. exotic far-field can be understood by sphere-image model that further reveals modes. presented results...
Orbital angular momentum (OAM) has emerged as an important parameter to store, control, and transport information using light. Recognizing optical beams that carry OAM at the nanoscale their interaction with subwavelength nanostructures turned out be a vital task in nanophotonic signal processing communication. The current platforms decode from different modes are mainly based on bulk optics requires sophisticated nanofabrication procedures. Motivated by these issues, herein we report...
We report on the experimental observation of beaming elastic and surface enhanced Raman scattering (SERS) emission from a bent-nanowire mirror (B-NWoM) cavity. The system was probed with polarization resolved Fourier plane energy-momentum imaging to study spectral angular signature wavevectors. out-coupled elastically scattered light kink occupies narrow spread. used self-assembled monolayer molecules well-defined molecular orientation utilize out-of-plane electric field in cavity for...
Spin-orbit interactions are subwavelength phenomena that can potentially lead to numerous device-related applications in nanophotonics. Here, we report the spin-Hall effect forward scattering of Hermite-Gaussian (HG) and Gaussian beams from a plasmonic nanowire. Asymmetric scattered radiation distribution was observed for circularly polarized beams. Asymmetry changes sign when polarization handedness inverts. We found significant enhancement HG beam compared constant input power. The...
Abstract The reduced dielectric screening in the out of plane direction, makes 2D materials sensitive to surrounding environment, offering a unique platform with greatly tunable optoelectronic properties. Large exciton binding energy limits their photogeneration efficiency. strong electric field generated at p–n junction will help separating these strongly bound electron hole pairs. Here, present study demonstrates how engineering environment would facilitate mixed dimensional van der Waals...
Influencing spectral and directional features of exciton emission characteristics from 2D transition metal dichalcogenides by coupling it to plasmonic nano-cavities has emerged as an important prospect in nanophotonics materials. In this paper we experimentally study the photoluminescence Tungsten disulfide (WS2) monolayer sandwiched between a single-crystalline silver nanowire (AgNW) waveguide gold (Au) mirror, thus forming AgNW-WS2-Au cavity. By employing polarization-resolved Fourier...
Herein we report experimental evidence of directional SERS from molecules situated inside a single nanowire-nanoparticle junction cavity. The emission was confined to narrow range wavevectors perpendicular the axis In addition this, excite multiple guided modes nanowire which were imaged using leakage radiation Fourier microscopy. We further characterize as function output polarization. excited wire show interesting polarization signatures. All results corroborated finite element method...
Directional harmonic generation is an important property characterizing the ability of nonlinear optical antennas to diffuse signal in a well-defined region space. Herein, we show how sub-wavelength facets organic molecular mesowire crystal can be utilized systematically vary directionality second-harmonic (SHG) forward-scattering geometry. We demonstrate this capability on crystalline diamonoanthraquinone (DAAQ) mesowires with facets. observed that radial angles SHG emission tuned over...
Single-layer two-dimensional (2D) nanomaterials exhibit physical and chemical properties which can be dynamically modulated through out-of-plane deformations. Existing methods rely on intricate micromechanical manipulations (e.g., poking, bending, rumpling), hindering their widespread technological implementation. We address this challenge by proposing an all-optical approach that decouples strain engineering from complexities. This method leverages the forces generated chiral light beams...
Abstract Room‐temperature phosphorescence of metal and heavy atom‐free organic molecules has emerged as an area great potential in recent years. A rational design played a critical role controlling the molecular ordering to impart efficient intersystem crossing stabilize triplet state achieve room‐temperature ultralong phosphorescence. However, most cases, strategies strengthen efficiency have resulted reduced lifetime, available nearly degenerate singlet‐triplet energy levels natural...
Engineering optical emission from two dimensional, transition metal dichalcogenides (TMDs) materials such as Tungsten disulphide (WS2) has implications in creating and understanding nanophotonic sources. One of the challenges controlling 2D is to achieve narrow angular spread using a simple photonic geometry. In this paper, we study how photoluminescence monolayer WS2 can be controlled when coupled film microsphere dielectric antenna. Specifically, by employing Fourier plane microscopy...
Vertical nanowires facilitate an innovative mechanism to channel the optical field in orthogonal direction and act as a nanoscale light source. Subwavelength, vertically oriented nanowire platforms, both of plasmonic semiconducting variety, can interesting far-field emission profiles potentially carry orbital angular momentum states. Motivated by these prospects, this Letter, we show how hybrid plasmonic-organic platform be harnessed engineer radiation. The system that have employed is...
Abstract In the era of next generation electronic technologies, pursuit reconfigurable circuitry is one key strategies for enhancing performance and functionality. The prevailing approach involves utilising individual components with dual functionality to provide reconfigurability. While valuable, this method remains an interim solution, necessitating a platform recurrent redesign tailored specific tasks. realisation technological leap hinges on spatially resolved, dynamic manipulation...
Surface-enhanced Raman spectroscopy(SERS) is a widely studied technique to enhance the signal of molecules. The high electric field near SERS substrate and large number optical density states, enable us detect single molecule their chemical specification. These locations are called hotspots which can be achieved in many ways: one interesting way harness fields nanocavity. Nanocavity assisted SERS(Surface-enhanced Scattering) context intensity enhancement, strong coupling, sensing capability...
Photoresponse Enhancement Huge enhancement in photoresponse is achieved by modulating the surrounding dielectric environment of a silicon-monolayer MoS2 heterostructure. Reduced charge carrier scattering along with lower binding energy excitons presence high contribute to this as reported article number 2102054 Vrinda Narayanan P., Atikur Rahman, and co-workers.