Prof. Lakshman S. Tamil Profile

Prof. Lakshman S. Tamil

Professor at Univ of Texas at Dallas

SPIE Involvement:

Author

Proceedings Article | 6 December 2005 Paper

Multi-terabit hybrid photonic switching and routing

Lakshman Tamil, Andrea Fumagalli

Proceedings Volume 6022, 60221N (2005) https://doi.org/10.1117/12.640176

KEYWORDS: Switching, Switches, Picosecond phenomena, Dense wavelength division multiplexing, Semiconductor optical amplifiers, Wavelength division multiplexing, Composites, Forward error correction, Associative arrays, Hybrid optics

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Proceedings Article | 8 February 2005 Paper

Optimized planning methodologies of ASON implementation

Michael Zhou, Lakshman Tamil

Proceedings Volume 5626, (2005) https://doi.org/10.1117/12.578505

KEYWORDS: Network architectures, Switches, Switching, Optical networks, Computer programming, Opacity, Multiplexing, Multiplexers, Mathematical modeling, Dense wavelength division multiplexing

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Proceedings Article | 22 September 2000 Paper

WDM fiber delay line buffer control for optical packet switching

Andrew Ge, Ljubisa Tancevski, Gerardo Castanon, Lakshman Tamil

Proceedings Volume 4233, (2000) https://doi.org/10.1117/12.401824

KEYWORDS: Wavelength division multiplexing, Switches, Packet switching, Computer simulations, Optical networks, Internet, Multiplexing, Channel projecting optics, Signal processing, Information operations

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Proceedings Article | 5 November 1999 Paper

Interaction of node-induced crosstalk with fiber nonlinearities in regional and metropolitan WDM networks

Tarek El-Bawab, HyunChin Kim, Israel Padilla, Lakshman Tamil

Proceedings Volume 3842, (1999) https://doi.org/10.1117/12.368324

KEYWORDS: Networks, Wavelength division multiplexing, Single mode fibers, Optical amplifiers, Eye, Modulation, Wavelength division multiplexing networks, Nonlinear optics, Receivers, Scanning probe microscopy

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Proceedings Article | 7 October 1998 Paper

Analysis of all-optical IP routers

Lakshman Tamil, Francesco Masetti, Thomas McDermott, Gerardo Castanon, Andrew Ge, Ljubisa Tancevski

Proceedings Volume 3531, (1998) https://doi.org/10.1117/12.327078

KEYWORDS: Switches, Multiplexing, Internet, Video, Device simulation, Data centers, Local area networks, Switching, Network architectures, Packet switching

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Proceedings Article | 2 January 1998 Paper

Synthesis of photonic devices by inverse scattering techniques

Lakshman Tamil

Proceedings Volume 3211, (1998) https://doi.org/10.1117/12.345525

KEYWORDS: Photonic devices, Inverse scattering, Wave propagation, Refractive index, Optical components, Quantum mechanics, Waveguides, Radio propagation, Optical amplifiers, Electromagnetic radiation

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The traditional procedure to synthesize optical devices with specified transmission characteristics is to start from device parameters such as refractive index profile with a known transmission characteristics that is close to the specified characteristics of the device and iteratively change the device parameters until the specified transmission characteristics of the device is achieved. This traditional procedure is time consuming and the choice of initial device parameters that has a transmission characteristics close to the specified characteristics is not always easy. However, techniques based on inverse scattering theory can directly provide the device design parameters given the specified transmission characteristics of the device. The inverse scattering techniques contrasts the traditional design procedure by their ability to yield design parameters in a non-iterative manner. The transmission of electromagnetic radiation in an optical waveguide is governed by vector wave equations which can be simplified to scalar wave equations under the assumption of “weakly guiding” approximation for TE and TM modes. The scalar equations obtained for TE and TM modes can be recast into Schrodinger type of equation that is normally encountered in quantum mechanics. One can draw an analogy between the quantum mechanical problem and the optical device problem. The potential well of the quantum mechanics corresponds to refractive index profile of the optical device problem; the time evolution of wave packets in quantum mechanics corresponds to propagation of optical modes along the axis in an optical device and the existence of discrete bound states in quantum mechanics is analogues to the presence of discrete propagating modes which in the geometrical-optics model corresponds to the modes that satisfy total internal reflection. Now, the refractive index profile; an important device parameter can be reconstructed from an assumed scattering coefficient that characterizes the specified transmission characteristics of the device. An analytical technique based on Gelfand-Levitan-Marchenko integral formulation and an numerical technique that extends the capability of the inverse techniques to provide solutions for generalized reflection coefficients that have been developed by us will be discussed. Design of a class of devices such as intra-chip optical interconnects, all-optical logic devices and efficient guiding structures for integrated optical amplifiers based on the inverse techniques will be discussed. The design of efficient guiding structures for optical amplifiers requires a guiding medium that has same propagation constant for both the signal and the pump. This leads to the inverse theory for reconstruction of energy dependent potentials or wavelength dependent refractive indices. We have solved this problem and we will show you a refractive index profile of a guiding structure obtained by inverse scattering technique that has same propagation constant at 1.55mm and 0.98/mm. The extension of the inverse techniques developed for planar structures to cylindrical structures is not straight forward, rather very cumbersome. However, we have succeeded in developing inverse scattering theory for the design of multimode cylindrical optical waveguides with same propagation constant for all modes and the design of single mode fiber that has the same propagation constants for more than one wavelength. Such structures will find application in image transmission and fiber amplifier design respectively. Our talk will include discussion of these cases.

Proceedings Article | 1 November 1990 Paper

Inverse-scattering theory applied to the synthesis of gradient-index optical waveguides

Lakshman Tamil, Arthur Jordan

Proceedings Volume 1351, (1990) https://doi.org/10.1117/12.23625

KEYWORDS: Waveguides

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Showing 5 of 7 publications

Conference Committee Involvement (1)

Network Architecture, Management, and Applications IV

5 September 2006 | Gwangju, South Korea

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