Author
Shubhayan Bhattacharya
Bio: Shubhayan Bhattacharya is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Whispering-gallery wave & Quantum dot. The author has an hindex of 4, co-authored 15 publications receiving 30 citations.
Papers
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TL;DR: In this paper, the temperature dependence of the whispering gallery modes of self-assembled microbottle resonators made of poly (methyl methacrylate) (PMMA) have been studied.
11 citations
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TL;DR: In this article, self-assembly of microbottle resonators (MBRs) that support high quality-factor (high- $Q$ ) whispering gallery modes (WGMs) has been demonstrated.
Abstract: We demonstrate self-assembly of microbottle resonators (MBRs) that support high-quality-factor (high- $Q$ ) whispering gallery modes (WGMs). Polymethyl methacrylate (PMMA), a transparent organic polymer, has been used for the self-assembly. Active MBRs have been created by doping PMMA with laser dye rhodamine 6G. WGM-modulated photoluminescence has been observed from the active MBRs. The self-assembled passive MBRs show $Q$ -factors of the order of $10^{6}$ . Fano- and electromagnetically induced transparency-type resonances have been observed in the transmission spectra.
10 citations
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TL;DR: In this paper, a one-pot synthesis pathway has been developed for carbon dots (CDs)-NaCl crystals formation at room temperature, and a new approach for realizing F-P lasing and white light emission from a non-toxic green source with a quick, facile and low-cost synthesis procedure.
Abstract: Phosphor materials with broad spectral range and an average emission lifetime (20 μs) have been achieved from carbon dots (CDs)-NaCl crystals. A one-pot synthesis pathway has been developed for CDs-NaCl crystals formation at room temperature. Precursor for CDs materials was screened at room temperature by oxidation methodology from different simple sugar molecules. CDs (size less than 10 nm) prepared from the fructose sugar exhibit most intense emission. Utilizing ripe banana peel (contains ∼27% of fructose) as a precursor for the carbon dot formation, white-light emission with a CIE index of (0.29, 0.34) has been achieved from the single source with CDs-NaCl crystals upon excitation at 430 nm. The crystals also function as Fabry-Perot (F-P) mode resonator for lasing, with a laser threshold value of 0.9 mW and a resonating Q-factor of 207. These results outline a new approach for realizing F-P lasing and white light emission from a non-toxic green source with a quick, facile and low-cost synthesis procedure.
9 citations
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TL;DR: In this paper, the fluorescence spectrum spans in the visible-near IR region (from 500nm to 900nm) with presence of prominent characteristic peaks of neutral and negatively charged NVs.
6 citations
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TL;DR: In this article, the authors synthesized and characterized the o-phenylenediamine doped graphene (G-f-OPD) to study the charge transfer with a standard laser dye rhodamine 6G (R6G).
6 citations
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TL;DR: This book presents the separation-of-variables and T-matrix methods of calculating the scattering of electromagnetic waves by particles, and the connection between the theory and the computer programs is reinforced by references in thecomputer programs to equations in the text.
Abstract: This book presents the separation-of-variables and T-matrix methods of calculating the scattering of electromagnetic waves by particles. Analytical details and computer programs are provided for determining the scattering and absorption characteristics of the finite-thickness slab, infinite circular cylinder (normal incidence), general axisymmetric particle, and sphere.The computer programs are designed to generate data that is easy to graph and visualize, and test cases in the book illustrate the capabilities of the programs. The connection between the theory and the computer programs is reinforced by references in the computer programs to equations in the text. This cross-referencing will help the reader understand the computer programs, and, if necessary, modify them for other purposes.
487 citations
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TL;DR: The optical properties of transition metal dichalcogenide monolayers are widely dominated by excitons, Coulomb-bound electron-hole pairs as mentioned in this paper, which give rise to narrow-band, well-pronounced optical transitions, which can be brought into resonance with electromagnetic fields in microcavities and plasmonic nanostructures.
Abstract: The optical properties of transition metal dichalcogenide monolayers are widely dominated by excitons, Coulomb-bound electron-hole pairs. These quasi-particles exhibit giant oscillator strength and give rise to narrow-band, well-pronounced optical transitions, which can be brought into resonance with electromagnetic fields in microcavities and plasmonic nanostructures. Due to the atomic thinness and robustness of the monolayers, their integration in van der Waals heterostructures provides unique opportunities for engineering strong light-matter coupling. We review first results in this emerging field and outline future opportunities and challenges.
185 citations
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TL;DR: The most recent advances in biosensing with whisperinggallery modes (WGMs) are described in this paper, where the basic concepts of WGM resonators, the integration of gain media into various active WGM sensors and devices, and the cutting-edge advances in photonic devices for micro-and nanoprobing of biological samples that can be integrated with WGM lasers.
Abstract: Lasers are the pillars of modern optics and sensing. Microlasers based on whispering-gallery modes (WGMs) are miniature in size and have excellent lasing characteristics suitable for biosensing. WGM lasers have been used for label-free detection of single virus particles, detection of molecular electrostatic changes at biointerfaces, and barcode-type live-cell tagging and tracking. The most recent advances in biosensing with WGM microlasers are described in this review. We cover the basic concepts of WGM resonators, the integration of gain media into various active WGM sensors and devices, and the cutting-edge advances in photonic devices for micro- and nanoprobing of biological samples that can be integrated with WGM lasers.
111 citations
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TL;DR: The authors combine nanostructured back-gate insulators with a continuous layer of graphene to demonstrate an electrically tunable two-dimensional photonic crystal suitable for controlling the propagation of surface plasmon polaritons.
Abstract: Photonic crystals are commonly implemented in media with periodically varying optical properties. Photonic crystals enable exquisite control of light propagation in integrated optical circuits, and also emulate advanced physical concepts. However, common photonic crystals are unfit for in-operando on/off controls. We overcome this limitation and demonstrate a broadly tunable two-dimensional photonic crystal for surface plasmon polaritons. Our platform consists of a continuous graphene monolayer integrated in a back-gated platform with nano-structured gate insulators. Infrared nano-imaging reveals the formation of a photonic bandgap and strong modulation of the local plasmonic density of states that can be turned on/off or gradually tuned by the applied gate voltage. We also implement an artificial domain wall which supports highly confined one-dimensional plasmonic modes. Our electrostatically-tunable photonic crystals are derived from standard metal oxide semiconductor field effect transistor technology and pave a way for practical on-chip light manipulation. Traditional photonic crystals consist of periodic media with a pre-defined optical response. Here, the authors combine nanostructured back-gate insulators with a continuous layer of graphene to demonstrate an electrically tunable two-dimensional photonic crystal suitable for controlling the propagation of surface plasmon polaritons.
48 citations
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TL;DR: In this paper, the progress in integration of nanodiamonds with photonic devices for quantum optics applications is discussed, and the results in GaP, SiO2 and SiC-nanodiamond platforms show that various regimes of light and matter interaction can be achieved by engineering color center systems through hybrid approaches.
Abstract: We discuss the progress in integration of nanodiamonds with photonic devices for quantum optics applications. Experimental results in GaP, SiO2 and SiC-nanodiamond platforms show that various regimes of light and matter interaction can be achieved by engineering color center systems through hybrid approaches. We present our recent results on the growth of color center-rich nanodiamond on prefabricated 3C-SiC microdisk resonators. These hybrid devices achieve up to five-fold enhancement of diamond color center light emission and can be employed for integrated quantum photonics.
43 citations