Prof. Debabrata Goswami Profile

Prof. Debabrata Goswami

Professor at Indian Institute of Technology Kanpur

SPIE Involvement:

Author

Area of Expertise:

Nonlinear Optics & Spectroscopy , Femtosecond Phenomena , Multiphoton Microscopy and Imaging , Optical Tweezers , Quantum Computing , Coherent Control

Websites:

Personal Website | Company Website

Profile Summary

Dr. Debabrata Goswami is the Prof. S. Sampath Endowed Chair Professor of Chemistry, and Senior Professor of Center for Lasers and Photonics of IIT Kanpur. He was the Vice President of the IEEE Photonics Society India, Past Chairman, Photonics-2016. Elected Fellow, Royal Society of Chemistry, the Institute of Physics (UK), OSA and the SPIE. He is the winner of the 2018 Galileo Galilei Award, the Thatachary Award, the Wellcome Trust Senior Research Fellowship, and the Swarnajayanti Fellow. He has over 200 publications.

Publications (24)

Proceedings Article | 5 October 2023 Presentation + Paper

Presentation + Paper

Applications and advantages of femtosecond optical tweezers

Debabrata Goswami

Proceedings Volume 12649, 126490K (2023) https://doi.org/10.1117/12.2682677

KEYWORDS: Particles, Optical tweezers, Femtosecond phenomena, Beam diameter, Fluorescence, Continuous wave operation, Pulsed laser operation, Microspheres, Ultrafast lasers, Refractive index

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Proceedings Article | 3 October 2022 Presentation + Paper

Presentation + Paper

Interplay of thermal and nonlinear processes for stable optical tweezers

Debabrata Goswami

Proceedings Volume 12198, 121980D (2022) https://doi.org/10.1117/12.2633345

KEYWORDS: Optical tweezers, Particles, Continuous wave operation, Pulsed laser operation, Refractive index, Thermal effects, Nonlinear optics, Ultrafast lasers, Kerr effect, Laser scattering

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Single-beam optical tweezers that use continuous wave (CW) lasers for trapping microscopic particles can be understood in terms of force-balancing light pressure from a tightly focused laser beam. High-repetition-rate femtosecond lasers for single-beam optical trapping research have matured as a technique and have garnered increasing interest. There are important differences between the theoretical models for femtosecond laser tweezers and the CW tweezers, e.g., in the sensitive detection of background-free two-photon fluorescence. The instantaneous trapping potential is due to the high peak power of each laser pulse, while the sustained stable trapping regime is a consequence of the high repetition rate of successive pulses. Simulating real-time scenarios for predicting optical trapping behavior continues to be a challenging problem. However, the capability and usefulness of optical tweezers setups with both CW and pulsed lasers are well established. For a tightly focused beam as used in an optical tweezer, cumulative heating can occur despite the minimal absorption cross-section of the trapping medium or the trapped particle, which reaches its maximum value near the focus. A temperature gradient from the laser focal spot is thus generated outwards from the laser focus in the medium, creating a refractive index gradient across the focusing region. The refractive index attains its minimum value at the focus, gradually increasing as a function of increasing distance from it. Since the trapping force and potential depend on the refractive index of the medium, the thermal effect impacts the force and potential of the trapped particle significantly. With CW lasers, computational evidence of temperature rise at the focus of optical tweezers has been posited, which, unfortunately, is not a feasible approach for ultrafast lasers, given their inherent computational complexities. A better understanding of high photon-flux induced processes and a working model of the single-beam optical tweezers that could address both CW and pulsed lasers would be ideal for elucidating the effects of this inherent thermal gradient of the optical tweezers. We demonstrate a framework that includes all possible nonlinear effects arising from high photon flux interactions and validate this with experimental results. Our approach allows a coherent and consistent treatment for both CW and ultrafast cases. We have the purely thermal nonlinear effects for the CW laser case, while for the ultrafast laser case, we include both the thermal and the Kerr type nonlinearities. Such a source-sensitive model is amenable to high throughput computations when coupled with a suitable paradigm for modeling experimental conditions as well.

Proceedings Article | 1 August 2021 Presentation + Paper

Presentation + Paper

On the spatiotemporal control with a single beam femtosecond optical tweezer

Debabrata Goswami

Proceedings Volume 11798, 117981Y (2021) https://doi.org/10.1117/12.2595198

KEYWORDS: Optical tweezers, Particles, Continuous wave operation, Thermal effects, Nonlinear optics, Refractive index, Femtosecond phenomena, Pulsed laser operation, Systems modeling, Kerr effect

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Proceedings Article | 23 April 2020 Presentation + Paper

Presentation + Paper

Sensing the insensible using optical schemes: converting the maze problem into a quantum search problem

Debabrata Goswami

Proceedings Volume 11388, 113880L (2020) https://doi.org/10.1117/12.2563658

KEYWORDS: Quantum communications, Quantum computing, Superposition, Image processing, Binary data, Data processing, Computer science, Chemistry, Optical design, Sensing systems

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Proceedings Article | 9 September 2019 Presentation + Paper

Presentation + Paper

Visualizing colloidal aggregation with femtosecond optical tweezers

Debabrata Goswami

Proceedings Volume 11083, 110832C (2019) https://doi.org/10.1117/12.2528518

KEYWORDS: Particles, Optical tweezers, Luminescence, Femtosecond phenomena, Polarization, Visualization, Pulsed laser operation, Objectives, Laser optics, Fluid dynamics

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Proceedings Article | 17 February 2017 Presentation + Paper

Presentation + Paper

Structured interferometry features in femtosecond supercontinuum: towards better understanding of supercontinuum for bio applications

Debabrata Goswami, Sirshendu Dinda, Soumendra Bandyopadhyay

Proceedings Volume 10060, 1006019 (2017) https://doi.org/10.1117/12.2253561

KEYWORDS: Femtosecond phenomena, Supercontinuum generation, Interferometry, Light sources, Imaging systems, Laser interferometry, Laser damage threshold, Superposition, Ultrafast imaging, Light, Visibility, Modulation, Optical filters, Wave propagation, Ions, Ultrafast phenomena

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Proceedings Article | 16 February 2017 Paper

Paper

In situ temperature control and measurement with femtosecond optical tweezers: offering biomedical application

Dipankar Mondal, Debabrata Goswami

Proceedings Volume 10068, 100681T (2017) https://doi.org/10.1117/12.2251892

KEYWORDS: Temperature metrology, Femtosecond phenomena, Optical tweezers, Near infrared, Molecules, Atmospheric particles, Pulsed laser operation, In situ metrology, Optical testing, Biomedical optics, Particles, Objectives, Calibration

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Proceedings Article | 16 September 2016 Paper

Paper

Temperature control and measurement with tunable femtosecond optical tweezers

Dipankar Mondal, Debabrata Goswami

Proceedings Volume 9922, 992210 (2016) https://doi.org/10.1117/12.2237708

KEYWORDS: Femtosecond phenomena, Optical tweezers, Absorption, Temperature metrology, Calibration, Particles, Molecules, Convection, Data acquisition, Cobalt

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SPIE Journal Paper | 5 May 2016

Sensitive in situ nanothermometer using femtosecond optical tweezers

Dipankar Mondal, Debabrata Goswami

JNP, Vol. 10, Issue 02, 026013, (May 2016) https://doi.org/10.1117/12.10.1117/1.JNP.10.026013

KEYWORDS: Optical tweezers, Femtosecond phenomena, Binary data, Temperature metrology, Absorption, Pulsed laser operation, Liquids, Bioalcohols, Objectives, Photodiodes

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Proceedings Article | 25 August 2015 Presentation + Paper

Presentation + Paper

Calibration of femtosecond optical tweezers as a sensitive thermometer

Dipankar Mondal, Debabrata Goswami

Proceedings Volume 9548, 95481N (2015) https://doi.org/10.1117/12.2187097

KEYWORDS: Femtosecond phenomena, Optical tweezers, Temperature metrology, Calibration, Absorption, Optical calibration, Data modeling, Lead, Fiber lasers, Photodiodes

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Proceedings Article | 15 June 2015 Paper

Paper

Measurement constraints in laser based thermal lens experiments

Debabrata Goswami, Pardeep Kumar

Proceedings Volume 9654, 965406 (2015) https://doi.org/10.1117/12.2192167

KEYWORDS: Laser beam diagnostics, Ultrafast lasers, Refractive index, Camera shutters, Data acquisition, Oscilloscopes, Laser applications, Spectroscopy, Chemical analysis, Transmittance

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Proceedings Article | 13 March 2013 Paper

Paper

Fluorescence advantages with microscopic spatiotemporal control

Debabrata Goswami, Debjit Roy, Arijit De

Proceedings Volume 8573, 857302 (2013) https://doi.org/10.1117/12.2009500

KEYWORDS: Luminescence, Particles, Microscopy, Optical tweezers, Picosecond phenomena, Femtosecond phenomena, Nanoparticles, Multiphoton microscopy, Pulsed laser operation, Continuous wave operation

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SPIE Journal Paper | 1 October 2011 Open Access

Open Access

Selective two-photon fluorescence suppression by ultrafast pulse-pair excitation: control by selective one-color stimulated emission

Arijit De, Debjit Roy, Debabrata Goswami

JBO, Vol. 16, Issue 10, 100505, (October 2011) https://doi.org/10.1117/12.10.1117/1.3645082

KEYWORDS: Luminescence, Absorption, Microscopy, Ultrafast phenomena, Picosecond phenomena, Multiphoton fluorescence microscopy, Multiphoton microscopy, Chemistry, Ultrafast lasers, Stimulated emission depletion microscopy

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Proceedings Article | 24 August 2011 Paper

Paper

Spectrally resolved femtosecond photon echo spectroscopy of astaxanthin

Ajitesh Kumar, S. K. Karthick Kumar, Aditya Gupta, Debabrata Goswami

Proceedings Volume 8173, 817325 (2011) https://doi.org/10.1117/12.899781

KEYWORDS: Spectroscopy, Femtosecond phenomena, Polarization, Optical amplifiers, Ultrafast phenomena, Molecules, Molecular spectroscopy, Visible radiation, Absorption, Phase matching

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Proceedings Article | 23 August 2011 Paper

Paper

Control of femtosecond laser driven retro-Diels-Alder-like reaction of dicyclopentadiene

Dipak Kumar Das, Tapas Goswami, Debabrata Goswami

Proceedings Volume 8173, 81730O (2011) https://doi.org/10.1117/12.897909

KEYWORDS: Ions, Femtosecond phenomena, Laser beam diagnostics, Molecular beams, Chemical reactions, Pulsed laser operation, Mass spectrometry, Ultrafast phenomena, Ultrafast lasers, Beam splitters

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SPIE Journal Paper | 1 November 2010 Open Access

Open Access

Selective suppression of two-photon fluorescence in laser scanning microscopy by ultrafast pulse-train excitation

Arijit Kumar De, Debjit Roy, Debabrata Goswami

JBO, Vol. 15, Issue 06, 060502, (November 2010) https://doi.org/10.1117/12.10.1117/1.3509383

KEYWORDS: Luminescence, Microscopy, Absorption, Laser scanners, Ultrafast phenomena, Pulsed laser operation, Beam splitters, Picosecond phenomena, Chemistry, Optical design

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Proceedings Article | 28 August 2010 Paper

Paper

Towards stable trapping of single macromolecules in solution

Arijit De, Debjit Roy, Debabrata Goswami

Proceedings Volume 7762, 776203 (2010) https://doi.org/10.1117/12.862364

KEYWORDS: Optical tweezers, Continuous wave operation, Particles, Pulsed laser operation, Macromolecules, Femtosecond phenomena, Calibration, Quantum dots, Luminescence, Latex

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Proceedings Article | 26 February 2010 Paper

Paper

Spatio-temporal control in multiphoton fluorescence laser-scanning microscopy

Arijit Kumar De, Debjit Roy, Debabrata Goswami

Proceedings Volume 7569, 756929 (2010) https://doi.org/10.1117/12.838287

KEYWORDS: Luminescence, Multiphoton fluorescence microscopy, Microscopy, Multiphoton microscopy, Pulsed laser operation, Femtosecond phenomena, Modulation, Absorption, Diffraction, Control systems

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SPIE Journal Paper | 1 November 2009 Open Access

Open Access

Ultrafast pulse-pair control in multiphoton fluorescence laser-scanning microscopy

Arijit De, Debabrata Goswami

JBO, Vol. 14, Issue 06, 064018, (November 2009) https://doi.org/10.1117/12.10.1117/1.3268440

KEYWORDS: Multiphoton fluorescence microscopy, Luminescence, Microscopy, Multiphoton microscopy, Pulsed laser operation, Absorption, Modulation, Ultrafast phenomena, Signal detection, Laser applications

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Proceedings Article | 20 August 2009 Paper

Paper

Towards spatio-temporal control in optical trapping

Debjit Roy, Arijit Kumar De, Debabrata Goswami

Proceedings Volume 7400, 74000G (2009) https://doi.org/10.1117/12.824372

KEYWORDS: Particles, Optical tweezers, Continuous wave operation, Femtosecond phenomena, Luminescence, Pulsed laser operation, Gaussian beams, Latex, Beam splitters, Mode locking

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Proceedings Article | 22 May 2009 Paper

Paper

Three-dimensional image formation under single-photon ultra-short pulsed illumination

Arijit De, Debabrata Goswami

Proceedings Volume 7378, 737827 (2009) https://doi.org/10.1117/12.822773

KEYWORDS: Confocal microscopy, Microscopy, Luminescence, Multiphoton microscopy, Pulsed laser operation, Absorption, 3D image processing, Multiphoton fluorescence microscopy, Live cell imaging, Second-harmonic generation

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Proceedings Article | 25 February 2009 Paper

Paper

Coherent control in multiphoton fluorescence imaging

Arijit Kumar De, Debabrata Goswami

Proceedings Volume 7183, 71832B (2009) https://doi.org/10.1117/12.807687

KEYWORDS: Multiphoton fluorescence microscopy, Pulsed laser operation, Absorption, Ultrafast lasers, Luminescence, Laser applications, Multiphoton microscopy, Microscopy, Amplitude modulation, Phase shift keying

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Proceedings Article | 17 September 2007 Paper

Paper

Nonlinear optical properties of free standing films of PbS quantum dots in the nonresonant femtosecond regime

Pushpa Ann Kurian, C. Vijayan, Amit Nag, Debabrata Goswami

Proceedings Volume 6639, 66390M (2007) https://doi.org/10.1117/12.733034

KEYWORDS: Absorption, Lead, Nonlinear optics, Quantum dots, Photoacoustic spectroscopy, Femtosecond phenomena, Transmittance, Optical limiting, Nanocrystals, Excitons

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Proceedings Article | 7 October 1998 Paper

Paper

Optical-wavelength-domain code division multiplexing using an AOM-based ultrafast optical pulse-shaping approach

Weiguo Yang, Jennifer Davis, Debabrata Goswami, Matthew Fetterman, Warren Warren

Proceedings Volume 3531, (1998) https://doi.org/10.1117/12.327047

KEYWORDS: Modulation, Ultrafast phenomena, Computer programming, Local area networks, Distortion, Channel projecting optics, Bragg cells, Optical fibers, Terahertz radiation, Optical pulse shaping

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Showing 5 of 24 publications

Conference Committee Involvement (2)

ICOL-2019

19 October 2019 |

Photonics-2016

4 December 2016 |

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