A5026013304- Photonic and Optical Devices
- Photonic Crystals and Applications
- Glass properties and applications
- Random lasers and scattering media
- Plasmonic and Surface Plasmon Research
- Photorefractive and Nonlinear Optics
- Luminescence Properties of Advanced Materials
- Silicon Nanostructures and Photoluminescence
- Orbital Angular Momentum in Optics
- Gold and Silver Nanoparticles Synthesis and Applications
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Neural Networks and Reservoir Computing
- Optical Coatings and Gratings
- Nonlinear Optical Materials Studies
- 2D Materials and Applications
- Advanced Fiber Optic Sensors
- Optical Coherence Tomography Applications
- Quantum Dots Synthesis And Properties
- ZnO doping and properties
- Perovskite Materials and Applications
- Quantum optics and atomic interactions
- Gas Sensing Nanomaterials and Sensors
- Advanced Optical Imaging Technologies
- Laser Material Processing Techniques
Indian Institute of Technology Kharagpur
2016-2025
Laboratoire de physique de la matière condensée
2010-2012
Centre National de la Recherche Scientifique
2008-2012
Université Côte d'Azur
2010-2012
Laboratoire de Physique Théorique de la Matière Condensée
2009-2012
Istituto di Fotonica e Nanotecnologie
2006-2011
Université de Lille
2007-2010
Laboratoire de Spectroscopie pour les Interactions, la Réactivité et l'Environnement
2007-2010
École Nationale Supérieure de Chimie de Lille
2010
Nello Carrara Institute of Applied Physics
2010
Although luminescence spectroscopy has been a promising sensing technology with widespread applications in point-of-care diagnostics and chem-bio detection, it fundamentally suffers from low signal collection efficiency, considerable background noise, poor photostability, intrinsic omnidirectional emission properties. In this regard, surface plasmon-coupled emission, versatile plasmon-enhanced detection platform >50% high directionality, polarization previously explored to amplify the limit...
Rare earth (RE)-doped silica-based optical fibers with transparent glass ceramic (TGC) core was fabricated through the well-known modified chemical vapor deposition (MCVD) process without going commonly used stage of postceramming. The main characteristics RE-doped oxide nanoparticles namely, their density and mean diameter in are dictated by concentration alkaline-earth element as phase-separating agent. Magnesium erbium co-doped were fabricated. Optical transmission term loss due to...
An active disordered medium able to lase is called a random laser (RL). We demonstrate lasing due inherent disorder in dye circulated structured microfluidic channel. consistently observe RL modes which are varied by changing the pumping conditions. Potential applications for on-chip sources and sensors discussed.
Abstract A variety of materials such as low dimensional carbon substrates (1D, 2D, and 3D), nanoprisms, nanocubes, proteins, ceramics, DNA to name a few, have been explored in surface plasmon-coupled emission (SPCE) platform. While these offer new physicochemical insights, investigations limited silver primary plasmonic material. Although, gold nanoparticles (AuNPs) exhibit robust performance, its intrinsic property quench the from radiating dipoles (at distances < 5 nm) has impeded...
The escalating concern about ohmic losses in metal-dependent plasmonics demands more effective material fabrication for the development of biosensing frameworks. omnidirectionality and low signal collection efficiency a conventional fluorescence-based detection platform make it challenging to realize better sensitivity real-time point-of-care diagnostics. In an attempt address these demands, recently photonic crystal-coupled emission (PCCE) has been demonstrated outperform well-established...
The intrinsically lossy nature of plasmonic-based detection platforms necessitates the use alternative nanophotonic such as one-dimensional photonic crystals (1DPhCs) to exploit properties pertaining stop band (PSB), Bloch surface waves (BSWs), microcavity, and band-edge modes. We present a highly desirable confinement internal optical modes (IOMs) large electromagnetic (EM) field due BSWs on plasmon-free, metal template-free, crystal-coupled emission (PCCE) platform ensuing 44-fold...
The unique functionality of metallic and dielectric nanomaterials to generate intense electromagnetic field localization termed "hotspots" has been exploited in numerous luminescence-based biosensing applications. To obtain an amplified, sharply directional, polarized emission, tunable size shape morphologies have evaluated the surface plasmon-coupled emission (SPCE) platform. Although such studies significantly facilitated biosensor modalities, inevitable parasitic Ohmic losses...
The nonlinear optical properties and the role of surface-plasmon resonance (SPR) on limiting (OL) Ag–Cu nanoclusters co-doped in SiO2 matrix prepared using sol-gel technique with a Cu∕Ag molar ratio 1, 2 3, respectively, are presented. studies were made second harmonic high-power nanosecond picosecond Nd:YAG lasers. These films show self-defocusing nonlinearity both pulses good absorption behavior pulse excitation. refractive index decreased decreasing particle size, whereas increased an...
We report on the sol-gel fabrication and characterization of (100−x)SiO2–xSnO2 (x=8, 16, 25mol%) glass-ceramic waveguides doped with 1mol% Eu3+. A suitable top-down thermal process led to formation SnO2 nanocrystals ∼4nm embedding Eu3+ ions. The excitation spectra evidence role interband electronic transition luminescence Monitoring D05→F27 emission, we observe about 15 times increase in intensity absorption band, moving from x=8to25mol%. These also exhibit low losses, making them quite...
Simultaneous occurrence of saturable absorption nonlinearity and two-photon in the same medium is well sought for devices like optical limiter laser mode-locker. Pristine graphene sheet consisting entirely sp2-hybridized carbon atoms has already been identified having large nonlinearity. However, oxide (GO), a precursor both sp2 sp3-hybridized atom, increasingly attracting cross-discipline researchers its controllable properties by reduction oxygen containing groups. In this work, GO...
Rare-earth doped transparent glass-ceramic waveguides are playing a very crucial role in integrated optics. We fabricated ZnO-HfO2 hybrid nanocrystals embedded with 70 SiO2–(30-x) HfO2–x ZnO (x = 0, 2, 5 and 7 mol %) ternary 1 % Eu-ions. The formation size of the evolved an increase concentration waveguides. In this context, key factors such active were optical losses transparency. A lab-built m-line experimental set-up was used for characterization On other hand, gain measurements Eu-doped...
Extended π-conjugation through the 2- and 6-positions of BODIPY core induces tunable yellow-red lasing with excellent efficiency up to 41% in toluene.
Abstract We report the observation of replica symmetry breaking (RSB) in a weakly scattering optofluidic random laser (ORL). Coherent lasing is indicated by presence narrow peaks rising out spectral background. This coherence helps to identify threshold, which expected be gradual with weak scattering. find that action initiated using optical pulsed pumping coincides onset both RSB and Lévy flight statistics. However, transition from photonic paramagnetic glass phase more subtle Parisi...
Optical Tamm structures have potential for the development of optoelectronic devices, provided they overcome challenge low-quality factor modes and inherent losses associated with plasmonic metal films. In this work, we present lasing in a super-Tamm structure consisting silver thin film deposited on 4-(dicyanomethylene)-2-methyl-6-(4- dimethylaminostyryl)-H-pyran (DCM) dye-doped polyvinyl alcohol (PVA) spacer layer coated SiO 2 /TiO one-dimensional photonic crystal threshold ∼0.07 mJ. The...
The authors report on one-dimensional dielectric photonic crystals activated by Er3+ ion and fabricated rf-sputtering deposition. cavity was constituted an Er3+-doped SiO2 active layer inserted between two Bragg reflectors consisting of six pairs SiO2∕TiO2 layers. Near infrared transmittance spectra evidence the presence a stop band from 1350to1850nm resonance centered at 1537nm. Intensity enhancement narrowing I13∕24→I15∕24 emission ion, due to effect, were observed. A quality factor 171 achieved.
Conventional lasers consist of two components: a gain material that is pumped in order to provide amplification light and cavity feedback. Random replace the traditional laser with random, multiple-scattering medium. This can give rise complex lasing behavior, such as unpredictable multidirectional multifrequency output. Controlling these systems has proved difficult and, until now, consisted structural manipulations. In random lasers, most common pumping mechanism an optical field, which be...
Strong light-matter interactions in layered transition metal dichalcogenides (TMDs) open up vivid possibilities for novel exciton-based devices. The optical properties of TMDs are dominated mostly by the tightly bound excitons and more complex quasiparticles, biexcitons. Instead physically exfoliated monolayers, solvent-mediated chemical exfoliation these 2D crystals is a cost-effective, large-scale production method suitable real device applications. We explore ultrafast excitonic processes...
Abstract Highly luminescent and direct band gap black phosphorus (BP) nanocrystals (NCs) synthesized using a cost‐effective sonochemical exfoliation route are reported. Microscopic studies have confirmed the of few‐layer nanoflakes BP NCs with variable average size between ≈2 ≈8 nm. Structural vibrational characteristics reveal superior crystalline quality by retaining phase symmetry in NCs. Size‐dependent absorption observed controlling nanoparticle show progressive blue shift near edge on...