Qualification: PhD, MIE, CEng (Institute of Engineering, India)

Dr. Kaustav Bhowmick currently serves as Assistant Professor(SG) at the department of Electronics and Communication Engineering, Amrita School of Engineering, Bengaluru campus.

Publications

Publication Type: Journal Article
Year of Publication Publication Type Title
2016 Journal Article K. Bhowmick, Furniss, D., Morvan, H. P., Seddon, A. B., and Benson, T. M., “Predictive, Miniature Co-Extrusion of Multilayered Glass Fiber-Optic Preforms”, Journal of the American Ceramic Society, vol. 99, pp. 106-114, 2016.[Abstract]

A miniature co-extrusion technique, to produce a concentric multilayered glass fiber-optic preform of ~3 mm diameter, is modeled and experimentally demonstrated. A three-dimensional, incompressible, noncavitating, and nonisothermal Computational Fluid Dynamics (CFD) model, similar to one developed in our previous work, is used to predict the dimensions of an alternating four-layer glass stack feed required to produce the desired layer dimensions in a multilayered-glass preform extrudate, using a miniaturized and thus more economical co-extrusion. Strong agreement in the cross-sectional geometrical proportions of the simulated and experimentally obtained preform supports the prowess of the predictive modeling. Nevertheless, some small deviations between the simulated and experimentally obtained dimensions indicate topics for future rheological study. Performing the co-extrusion process under vacuum helps to minimize the inter-layer defects in the multi-layered fiber-optic preform. The miniature co-extrusion potentially removes the need for a postextrusion draw-down prior to fiber drawing, avoiding devitrification issues possible in non-oxide novel glass compositions. © 2015 The American Ceramic Society.

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2013 Journal Article K. Bhowmick, Morvan, H. P., Furniss, D., Seddon, A. B., and Benson, T. M., “Co-Extrusion of Multilayer Glass Fiber-Optic Preforms: Prediction of Layer Dimensions in the Extrudate”, Journal of the American Ceramic Society, vol. 96, pp. 118–124, 2013.[Abstract]

A three-dimensional, incompressible and noncavitating model of a glass-stack coextrusion process, under isothermal and non-isothermal conditions is numerically simulated by means of computational fluid dynamics. A dynamic mesh approach is taken in a domain-subdomain type setup to simulate the transient steps in the steady-velocity phase of the experimental co-extrusion. The multiphase setup consists of a glass-stack which is composed of different glass compositions. Experimentally measured glass properties, such as the temperature coefficient of the viscosity of the supercooled glass melts are used to define the flow behavior of the glasses in the starting stack when extruded. The modeled extrudate is numerically verified for transient and spatial errors, leading to the choice of a suitable mesh. Excellent agreement is found between modeling and experiment when plotting the core/cladding dimensions of a step-index extruded fiber-optic preform along the length of the preform. This approach can identify the stable part of the preform, in terms of constant core/cladding layer geometry, obviating costly and time-consuming experimental iteration. Also, the modeling allows prediction of the starting glass-stack dimensions for a specified fiber design.

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Publication Type: Conference Paper
Year of Publication Publication Type Title
2013 Conference Paper K. Bhowmick, “ANSYS for fiber-optics and novel photonic glass extrusion”, in 9th ASEAN ANSYS Conference, Singapore, 2013.[Abstract]

A general, three-dimensional, incompressible and non-cavitating model of a glass stack coextrusion was developed and simulated using ANSYS-CFX. The model was used to simulate a core/clad chalcogenide glass-pair coextrusion, previously accomplished towards the first multilayer chalcogenide glass fiber. Experimentally measured essential chalcogenide glass properties like thermal expansion coefficient, were used to define the respective glass material models. A dynamic mesh approach was applied to simulate the transient steps of the extrusion. The dimensions in the resulting structure of the simulated extrudate were compared with experimental results and a very close agreement was obtained. This indicates that such computational fluid dynamics modelling can potentially be used as a predictive tool for complicated fiber-optic structures involving multiple material.

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2008 Conference Paper K. Bhowmick, Benson, T. M., Boriskina, S. V., Kuhl, U., and Stöckmann, H. J., “Spectral Response and Emission Characteristics of Isolated and Clustered Micro-resonators”, in PIERS 2008, Cambridge, USA., 2008.[Abstract]

Photonic structures with dimensions comparable to the operating wavelength have been studied widely of late, especially the performance of micro-resonators supporting Whispering Gallery modes (WGMs). Coupled assemblies of two or more resonators have also proved of great interest in the optical regime where they have been shown to offer further control over pertinent properties such as Q-factor, modal volume and emission or sensing properties. These coupled resonator structures have been called photonic molecules (PMs) due to the similarity between their mode structure and the electron orbital structure found in the chemical molecules that they resemble in structural geometry. Microwave scale models of optical micro-resonators, excited at microwave frequencies, demonstrate similar resonant features to the corresponding optical structures and so provide an extremely useful experimental tool with which to explore the properties of photonic molecules [1, 2]. Dielectric materials used to fabricate the microwave models are easily available and comparatively inexpensive. Further, the dimensions being in the larger centimetre-scale, the structures can be conveniently fabricated with high precision. In this presentation we describe the results of such microwave-scale experiments to determine the resonant and directional emission properties of (i) single resonators with various geometries, including notched microdisk resonators [3], and (ii) an assortment of geometrical arrangements of similar and dissimilar (size-mismatched) microresonators.
Comparisons are made with the predictions of numerical simulations based on an integral equation analysis.

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Professional Body Membership

  • Reviewer for Journal of American Ceramic Society
  • Reviewer for Optical and Quantum Electronics Journal, Springer
  • Member and Chartered Engineer (CEng), Institution of Engineers, India
     

Course Levels Taken

  • B. Tech., M. Tech., Ph. D. coursework
Faculty Details

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Faculty Email: 
k_bhowmick@blr.amrita.edu