Browsing by Author "Jaroszewicz, Z"

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ENERGY FLUX DENSITY FOR HIGHER-ORDER CYLINDRICAL VECTOR VORTEX BEAM TIGHTLY FOCUSED THROUGH A DIELECTRIC INTERFACE
(Springer Link, 2021-08-25) Lavanya, M; Thiruarul, D; Rajesh, K B; Mahadevan, G; Dhayalan, Velauthapillai; Jaroszewicz, Z
Energy flux density for higher-order cylindrical vector vortex (HCVV) beam focused through a dielectric interface is analyzed numerically based on vector diffraction theory. Numerical results shows variation in the direction of the energy flux or Poynting vector distribution both in transverse and longitudinal plane upon suitably tuning the topological charge and polarization order of HCVV beam. We also note that the strong reverse flow of energy occur at the centre of the focal plane for certain values of the topological charge and polarization order. These results may find potential applications in optical trapping and optical manipulations.
GENERATION OF MULTIPLE FOCAL PATTERN VIA PHASE MODULATED RADIAL AND AZIMUTHAL VARIANT VECTOR BEAM
(Springer Link, 2023-03-07) Thiruarul, D; William Charles, J; Lavanya, M; Rajesh, K B; Jaroszewicz, Z
The multiple focal patterns such as longitudinally/transversely polarized multiple focal spots/holes, longitudinally/transversely polarized annular dark multiple spots with petal shapes are in high demand for applications such as multiple optical trapping and manipulating, light-sheet fluorescence microscopy and optical lithography. This article numerically demonstrated the possibility of achieving the above task by subjecting phase modulation of radial and azimuthal variant vector beam through suitable annular Walsh function filter. Here it is demonstrated that the inherited self similarity properties of annular Walsh function and the flexibility of tuning the radial and azimuthal index of input beam is a state of art in landscaping multiple focal segment of desirable spatial and polarization distribution.
GENERATION OF SUB-WAVELENGTH LONGITUDINAL MAGNETIC PROBE AND MULTIPLE SPOTS USING CIRCULARLY POLARIZED ANNULAR MULTI-GAUSSIAN BEAM
(Springer Link, 2019-11-13) Seethalakshmi, S; Udhayakumar, M; Priyadharsini, N; Rajesh, K B; Jaroszewicz, Z
Based on vector diffraction theory and inverse Faraday effect, we numerically studied the magnetization induced by a tightly focused circularly polarized annular multi-Gaussian beam. Numerical result shows that the magnetization spot as small as 0.4 λ which extends up to 8 λ can be induced for incident circularly polarized annular multi-Gaussian beam (CPAMGB). We also noted that the depth of focus of the generated magnetization spot can be very well improved up to 48 λ through suitable phase modulation to the incident CPAMGB by means of specially designed complex phase filter. Moreover, we also noted that one can generate a chain of magnetization spots of different numbers and sizes upon suitably changing the beam order of CPAMGB and radii of complex phase filter. We expect that such a study will be fruitful for experimental realization of all-optical magnetic recording, multiple magnetic particle trapping and transportation, confocal and magnetic resonance microscopy, as well as multilayer ultra-high-density magnetic storage.
GENERATION OF SUB-WAVELENGTH LONGITUDINAL MAGNETIZATION NEEDLE AND MULTIPLE LONGITUDINAL SPOTS USING CIRCULARLY POLARIZED BEAM THROUGH AN ANNULAR WALSH FUNCTION FILTER
(Springer, 2024-07) Thiruarul, D; Charles J, William; Lavanya, M; Rajesh, K.B; Jaroszewicz, Z
This numerical work demonstrates the possibility of generating sub wavelength scale magnetization spot of long focal depth and axially separated multiple magnetization segments using annular Walsh function filter. Numerical result calculated on the basis of vector diffraction theory (VDT) and Inverse Faraday Effect (IFE) shows upon suitably choosing the parameters of Walsh function filter such as order and annular obstruction, one can generate and tune the longitudinal magnetization needle and multiple magnetization spots in the focal plane for the input circularly polarized Bessel Gaussian beam. The generated sub wavelength magnetization structures are highly applicable in fields such as all-optical magnetic recording, multiple trapping and transportation of magnetic particles, magnetic resonance microscopy and multilayer ultra-high-density magnetic storage.
GENERATION OF ULTRA-LONG MULTIPLE OPTICAL TUBES USING ANNULAR WALSH FUNCTION FILTERS
(Springer Link, 2020-08-29) Thiruarul, D; Rajesh, K B; Lavanya, M; Mahadevan, G; Dhayalan, Velauthapillai; Jaroszewicz, Z
The tight focusing properties of an azimuthally polarized Bessel Gaussian beam phase modulated by annular Walsh function filter is studied numerically by vector diffraction theory. It is observed that upon suitable optimization of order and annular obstruction ratio of an annular Walsh function filter, one can generate multiple sub wavelength scale optical tubes (optical holes) with super long focal depth. Such a focal system is usable for Nano-lithography, particle trapping and transportation, as well as confocal and STED microscopy, microstructure fabrication etc.
PLATINUM LAYERS SANDWICHED BETWEEN BLACK PHOSPHOROUS AND GRAPHENE FOR ENHANCED SPR SENSOR PERFORMANCE
(Springer, 2022-02-01) Pandaram, M; Santhanakumar, S; Veeran, R; Balasundaram, R K; Jha, R; Jaroszewicz, Z
Highly sensitive surface plasmon resonance (SPR) sensor consisting of Ag-Pt bimetallic films sandwiched with 2D materials black phosphorus (BP) and graphene over Pt layer in Kretschmann configuration is analyzed theoretically using the transfer matrix method. Numerical results show that upon suitable optimization of thickness of Ag-Pt layers and the number of layers of BP and graphene, sensitivity as high as 412°/RIU (degree/refractive index unit) can be achieved for p-polarized light of wavelength 633 nm. This performance can be tuned and controlled by changing the number of layers of BP and graphene. Furthermore, the addition of graphene and heterostructures of black phosphorus not only improved the sensitivity of the sensor but also kept the FWHM of the resonance curve much smaller than the conventional sensor utilizing Au as plasmonic metal and hence improved the resolution to a significant extent. We expect that this new proposed design will be useful for medical diagnosis, biomolecular detection, and chemical examination.
SENSITIVITY ENHANCEMENT OF SURFACE PLASMON RESONANCE SENSOR USING HYBRID CONFIGURATION OF 2D MATERIALS OVER BIMETALLIC LAYER OF CU–NI
(Elsevier, 2020-05-15) AlaguVibisha, G; Jeeban Kumar, Nayak; Maheswari, P; Priyadharsini, N; Nisha, A; Jaroszewicz, Z; Rajesh, K B; Rajan, Jha
This Theoretical study aims at improving the sensitivity of surface plasmon resonance biosensor under angular interrogation. We observed that the sensor configuration composed of bimetallic layer of Cu–Ni attached with 2D materials MoS2/WS2/MoSe2/WSe2/graphene enhanced the sensitivity of the sensor to a great extends. The thickness of the bimetallic layers and the number of layers of 2D materials are optimized to achieve maximum sensitivity. Numerical results shows that sensitivity as high as 480 /RIU is achieved for the well optimized bimetallic configuration consist of 35 nm of Cu and 20 nm of Ni thickness for the analyte refractive indices ranging from 1.33–1.335. Up on functionalizing the metal layers with bimolecular recognizing 2D materials, we noted that configuration with 35 nm of Cu, 15 nm of Ni with monolayer of 2D material WS2 enhanced the sensitivity as high as 426 /RIU. We expect that such a simple structure and promising results will lead the proposed sensor as a suitable and potential candidate for detecting biomolecules organic elements and other analytes.
SENSITIVITY ENHANCEMENT OF SURFACE PLASMON RESONANCE SENSOR WITH 2D MATERIAL COVERED NOBLE AND MAGNETIC MATERIAL (NI)
(Springer Link, 2019-01-01) Nisha, A; Maheswari, P; Anbarasan, P M; Rajesh, K B; Jaroszewicz, Z
In this paper, surface plasmon resonance (SPR) sensor on 2D materials such as MoS2 and graphene on Au and magnetic material Ni in Kretschmann configuration is analyzed using transfer matrix method. Here we noted that by sandwiching the MoS2 layer between the Au and Ni film and adding graphene over Ni film improved the sensitivity as high as 229°/RIU. We also noted that the sensitivity of the proposed sensor changes with the addition of no. of layers of graphene and MoS2. We expect that such a high sensitivity SPR sensor could find optional application in chemical examination, medical diagnostic and biological detections.
TIGHT FOCUSING PROPERTIES OF AZIMUTHALLY POLARIZED PAIR OF VORTEX BEAMS THROUGH A DIELECTRIC INTERFACE
(IOP Publishing Ltd, 2017) Janet, C A P; Lavanya, M; Rajesh, K B; Udhayakumar, M; Jaroszewicz, Z; Velauthapillai, D
Tight focusing properties of an azimuthally polarized Gaussian beam with a pair of vortices through a dielectric interface is theoretically investigated by vector diffraction theory. For the incident beam with a pair of vortices of opposite topological charges, the vortices move toward each other, annihilate and revive in the vicinity of focal plane, which results in the generation of many novel focal patterns. The usable focal structures generated through the tight focusing of the double-vortex beams may find applications in micro-particle trapping, manipulation, and material processing, etc.