Subhajit Chakraborty

IIT Kanpur

Education / Work History

  • Ph.D. Scholar, IIT Kanpur (2018-present)
  • M.Tech., IIT Delhi (2018)
  • M.Sc., SKBU Purulia (2016)
  • B.Sc., SKBU Purulia (2014)

Research Topic / Interest

My main interests are currently:

  • Multiphoton Microscopy
  • Thermal lens Spectroscopy

Publications

These will include only those published in our lab.

  1. Diluting Convective Effects in Femtosecond Laser Induced Thermal Lens Measurements with Thermally Active Constituents. S. Chakraborty, A. K. Mishra, A. K. Rawat, and D. Goswami, in Frontiers in Optics + Laser Science 2022 (FIO, LS) (2022), Paper JW5A.25 (Optica Publishing Group, 2022), p. JW5A.25 [Abstract] [PDF] [BibTeX]

    Abstract: We report Thermal Lens measurements on the binary liquid mixtures of Methanol and Phenol with femtosecond pulse excitations. The photothermal response is found to be strongly dependent on relative concentrations and the constituents’ molecular properties.

     BibTeX: @inproceedings{chakrabortyDilutingConvectiveEffects2022,
  title = {Diluting {{Convective Effects}} in {{Femtosecond Laser Induced Thermal Lens Measurements}} with {{Thermally Active Constituents}}},
  booktitle = {Frontiers in {{Optics}} + {{Laser Science}} 2022 ({{FIO}}, {{LS}}) (2022), Paper {{JW5A}}.25},
  author = {Chakraborty, Subhajit and Mishra, Amit Kumar and Rawat, Ashwini Kumar and Goswami, Debabrata},
  date = {2022-10-17},
  pages = {JW5A.25},
  publisher = {{Optica Publishing Group}},
  url = {https://opg.optica.org/abstract.cfm?uri=FiO-2022-JW5A.25},
  urldate = {2022-12-31},
  eventtitle = {Frontiers in {{Optics}}}
}
  2. An Investigation of Evanescent Wave-Induced Fluorescence Spectroscopy for Exploring High Refractive Index Media. S. Chakraborty, Y. Xu, A. Roberts, D. Goswami, and T. A. Smith, Physica Scripta 98(1), 015014 (2022) [Abstract] [PDF] [BibTeX]

    Abstract: Evanescent wave-induced fluorescence spectroscopy (EWIFS) is a widely used technique for probing the interfacial behavior of different complex media in investigations of samples in the physical, chemical, and biological sciences. This technique takes advantage of the sharply decaying evanescent field, established following total internal reflection (TIR) at the interface of two media, for spatially identifying the photoluminescence characteristics of the sample. The generation of the evanescent field requires the refractive index of the second medium to be lower than that of the first, so a major disadvantage of this increasingly widely used spectroscopic technique is the inability to exploit the advantages of EWIFS to image a sample with a higher refractive index than the incident substrate medium. A proposed configuration in which a thin, low refractive index intermediate layer is established between the TIR substrate and a high refractive index sample is investigated. We illustrate that this arrangement does not afford the desired advantages of evanescent field-induced fluorescence measurements for investigating high refractive index media.

     BibTeX: @article{chakrabortyInvestigationEvanescentWaveinduced2022,
  title = {An Investigation of Evanescent Wave-Induced Fluorescence Spectroscopy for Exploring High Refractive Index Media},
  author = {Chakraborty, Subhajit and Xu, Yang and Roberts, Ann and Goswami, Debabrata and Smith, Trevor A.},
  date = {2022-12},
  journaltitle = {Physica Scripta},
  shortjournal = {Phys. Scr.},
  volume = {98},
  number = {1},
  pages = {015014},
  publisher = {{IOP Publishing}},
  issn = {1402-4896},
  doi = {10.1088/1402-4896/aca437},
  url = {https://dx.doi.org/10.1088/1402-4896/aca437},
  urldate = {2022-12-31}
}
  3. Quality Assessment of the Commercially Available Alcohol-Based Hand Sanitizers with Femtosecond Thermal Lens Spectroscopy. S. Chakraborty, A. K. Rawat, A. K. Mishra, and D. Goswami, PeerJ Analytical Chemistry 5, e25 (2023) [Abstract] [PDF] [BibTeX]

    Abstract: Using femtosecond-pulse-induced thermal lens spectroscopy (FTLS), we report a novel method for the quality measurements of alcohol-based hand sanitizers (ABHS). To sustain its effectiveness, the ABHS must contain the recommended concentration of alcohol content. We diluted the hand sanitizer with water to reduce the quantity of alcohol in the mixture and then performed thermal measurements on it. We performed both dual-beam Z-scan and time-resolved TL measurements to identify the alcoholic content in the ABHS. The thermal lens (TL) signal of the solvent is capable of detecting any relative change in the alcohol content in the mixture. Our technique, therefore, emerges as a sensitive tool for quality testing of alcohol-based hand sanitizers.

     BibTeX: @article{chakrabortyQualityAssessmentCommercially2023,
  title = {Quality Assessment of the Commercially Available Alcohol-Based Hand Sanitizers with Femtosecond Thermal Lens Spectroscopy},
  author = {Chakraborty, Subhajit and Rawat, Ashwini Kumar and Mishra, Amit Kumar and Goswami, Debabrata},
  date = {2023-05-30},
  journaltitle = {PeerJ Analytical Chemistry},
  shortjournal = {PeerJ An. Chem.},
  volume = {5},
  pages = {e25},
  publisher = {{PeerJ Inc.}},
  issn = {2691-6630},
  doi = {10.7717/peerj-achem.25},
  url = {https://peerj.com/articles/achem-25},
  urldate = {2023-07-28}
}
  4. Sensing the Molecular Properties in Methanol and Its Binary Mixtures Using Time-Resolved Thermal Lens Spectrometer. S. Chakraborty, A. K. Rawat, and D. Goswami, in 2019 Workshop on Recent Advances in Photonics (WRAP) (2019), pp. 1–3 [Abstract] [BibTeX]

    Abstract: Mode Mismatched Pump-Probe spectroscopic method was employed to examine the thermally induced nonlinear optical properties of methanol and its binary mixtures. The heat transfer mechanism in methanol and its binary mixtures with carbon tetrachloride (CCl4) at different concentrations of methanol is investigated. Methanol has the highest Thermal Lens (TL) signal, and CCl4 does not have any TL signal at all. However, the presence of CCl4 modulates the TL signal of the binary mixture. The time-domain shift in TL signal is observed for different concentrations of methanol, which indicates the unusual molecular behavior in the binary mixture.

     BibTeX: @inproceedings{chakrabortySensingMolecularProperties2019,
  title = {Sensing the {{Molecular Properties}} in {{Methanol}} and Its {{Binary Mixtures}} Using {{Time-Resolved Thermal Lens Spectrometer}}},
  booktitle = {2019 {{Workshop}} on {{Recent Advances}} in {{Photonics}} ({{WRAP}})},
  author = {Chakraborty, Subhajit and Rawat, Ashwini Kumar and Goswami, Debabrata},
  date = {2019-12},
  pages = {1--3},
  issn = {null},
  doi = {10.1109/WRAP47485.2019.9013697},
  eventtitle = {2019 {{Workshop}} on {{Recent Advances}} in {{Photonics}} ({{WRAP}})}
}
  5. Understanding the Photothermal Response of CBNP Nanofluids Using Thermal Lens Spectroscopic Techniques. S. Chakraborty, A. K. Mishra, A. K. Rawat, and D. Goswami, in Frontiers in Optics + Laser Science 2021 (2021), Paper JTu1A.99 (Optica Publishing Group, 2021), p. JTu1A.99 [Abstract] [PDF] [BibTeX]

    Abstract: We performed a dual beam Z-Scan experiment to examine the thermal lensing effects in CBNP nanofluids. The photothermal characteristics and heat dissipation dynamics were observed for these nanofluids at different levels of their linear absorption.

     BibTeX: @inproceedings{chakrabortyUnderstandingPhotothermalResponse2021,
  title = {Understanding the {{Photothermal Response}} of {{CBNP Nanofluids Using Thermal Lens Spectroscopic Techniques}}},
  booktitle = {Frontiers in {{Optics}} + {{Laser Science}} 2021 (2021), Paper {{JTu1A}}.99},
  author = {Chakraborty, Subhajit and Mishra, Amit Kumar and Rawat, Ashwini Kumar and Goswami, Debabrata},
  date = {2021-11-01},
  pages = {JTu1A.99},
  publisher = {{Optica Publishing Group}},
  doi = {10.1364/FIO.2021.JTu1A.99},
  url = {https://opg.optica.org/abstract.cfm?uri=LS-2021-JTu1A.99},
  urldate = {2022-12-31},
  eventtitle = {Laser {{Science}}}
}
  6. Achieving Molecular Distinction in Alcohols with Femtosecond Thermal Lens Spectroscopy. A. Kumar Rawat, S. Chakraborty, A. Kumar Mishra, and D. Goswami, Chemical Physics 561, 111596 (2022) [Abstract] [PDF] [BibTeX]

    Abstract: Using thermal lens (TL) spectroscopy, we distinguish monohydric alcohols based on their molecular characteristics and thermophysical properties. We use both dual-beam Z-scan and time-resolved TL measurements to identify thermal signatures of the representative homologous series of aliphatic, cyclic, and aromatic alcohols. While, in aliphatic alcohols, TL signal amplitude depends strongly on the molecular size and chain length; for cyclic and aromatic alcohols, their photophysical characteristics exhibit dominance over the molecular influence of TL signal. The convective properties of short-chain molecules result in a characteristic trend in dual-beam experiments. Methanol displays the lowest steady-state TL signal due to its fast diffusive capabilities. At the same time, phenol shows the most prominent steady-state TL signal owing to its strong H-bonded cluster formation ability through resonant structures. TL measurements successfully distinguish alcohols belonging to the respective homologous series and additionally discern solvents with a similar number of carbon atoms belonging to different homologous series.

     BibTeX: @article{kumarrawatAchievingMolecularDistinction2022,
  title = {Achieving Molecular Distinction in Alcohols with Femtosecond Thermal Lens Spectroscopy},
  author = {Kumar Rawat, Ashwini and Chakraborty, Subhajit and Kumar Mishra, Amit and Goswami, Debabrata},
  date = {2022-09-01},
  journaltitle = {Chemical Physics},
  shortjournal = {Chemical Physics},
  volume = {561},
  pages = {111596},
  issn = {0301-0104},
  doi = {10.1016/j.chemphys.2022.111596},
  url = {https://www.sciencedirect.com/science/article/pii/S0301010422001513},
  urldate = {2022-12-31}
}
  7. Poly-Lysinated Nanoscale Carbon Probe for Low Power Two-Photon Bioimaging. S. Kundu, N. Chatterjee, S. Chakraborty, A. Gupta, D. Goswami, and S. K. Misra, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 270, 120778 (2022) [BibTeX] 
     BibTeX: @article{kunduPolylysinatedNanoscaleCarbon2022,
  title = {Poly-Lysinated Nanoscale Carbon Probe for Low Power Two-Photon Bioimaging},
  author = {Kundu, Sayan and Chatterjee, Niranjan and Chakraborty, Subhajit and Gupta, Arjit and Goswami, Debabrata and Misra, Santosh K.},
  date = {2022},
  journaltitle = {Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy},
  volume = {270},
  pages = {120778},
  publisher = {{Elsevier}}
}
  8. Investigating the pH Dependence of Thermal Signatures in Monohydric and Polyhydric Alcohols Using Time-Resolved Thermal Lens Spectroscopy. A. K. Rawat, S. Chakraborty, A. K. Mishra, and D. Goswami, Optical Materials 137, 113623 (2023) [Abstract] [PDF] [BibTeX]

    Abstract: We study the influence of pH on the thermophysical properties of monohydric and polyhydric alcohols through a femtosecond laser-induced thermal lens (TL) spectroscopic technique. Relative changes in the thermal signatures of monohydric and polyhydric alcohols are identified at different pH levels using both dual-beam Z-scan and time-resolved TL measurements. We found the TL signatures of the alcohols not to be affected in the acidic region, but a significant change is noticed in the alkaline environment. It is observed that in an alkaline environment (pH > 7), the TL signal significantly increases for short-chain (MeOH and EtOH) monohydric alcohols. In contrast, the TL signal for longer chain length monohydric alcohols (HxOH and phenol) and polyhydroxy alcohols (Ethylene glycol & Glycerol) fall enormously. These results depend strongly on the molecular characteristics of solvents and their interaction strength with the solute as a function of changing pH strength. Our results show the influence of pH on the natural drifting and the heat dissipation characteristics of solvent molecules, which prominently participate in changing the TL signatures of samples. This event could be attributed to changes in molecular arrangements by developing solvation shells (through ions-solvents interactions) in the systems. We investigate the influence of various factors, namely, chain length, structure, polarity, and inter or the intra-H-bonding ability of solvent molecules and ion concentration, which effectively alter the solute-solvent interaction strengths at different pH values (especially in an alkaline environment). The findings through our TL measurements explore this event in great detail for the first time. We try to correlate the molecular characteristics and its ions-solvent interaction effects with the thermophysical properties of alcohols.

     BibTeX: @article{rawatInvestigatingPHDependence2023,
  title = {Investigating the {{pH}} Dependence of Thermal Signatures in Monohydric and Polyhydric Alcohols Using Time-Resolved Thermal Lens Spectroscopy},
  author = {Rawat, Ashwini Kumar and Chakraborty, Subhajit and Mishra, Amit Kumar and Goswami, Debabrata},
  date = {2023-03-01},
  journaltitle = {Optical Materials},
  shortjournal = {Optical Materials},
  volume = {137},
  pages = {113623},
  issn = {0925-3467},
  doi = {10.1016/j.optmat.2023.113623},
  url = {https://www.sciencedirect.com/science/article/pii/S0925346723001957},
  urldate = {2023-07-28}
}
  9. Thermal Inflection Study of Methanol-Hexane Mixtures Using Time-Resolved Thermal Lens Technique. A. K. Rawat, S. Chakraborty, and D. Goswami, in 2019 Workshop on Recent Advances in Photonics (WRAP) (2019), pp. 1–3 [Abstract] [PDF] [BibTeX]

    Abstract: Time-resolved thermal lens (TL) technique is used to measure the heat transfer in pure methanol and its binary mixtures with hexane. We used dual-beam mode mismatched pump-probe scheme where a femtosecond laser beam of 1560 nm was used as a pump beam, and its frequency-doubled 780 nm beam was used as probe beam. TL Signal decreases with increasing concentration of hexane in the binary mixture. On higher concentration of Hexane in binary mixture then we have found convective heat transfer mode was absent. At 40%-60% methanol hexane mixture, we observed a sudden curious jump in TL signal.

     BibTeX: @inproceedings{rawatThermalInflectionStudy2019,
  ids = {rawatThermalInflectionStudy2019a},
  title = {Thermal {{Inflection Study}} of {{Methanol-Hexane Mixtures}} Using {{Time-Resolved Thermal Lens Technique}}},
  booktitle = {2019 {{Workshop}} on {{Recent Advances}} in {{Photonics}} ({{WRAP}})},
  author = {Rawat, Ashwini Kumar and Chakraborty, Subhajit and Goswami, Debabrata},
  date = {2019-12},
  pages = {1--3},
  issn = {null},
  doi = {10.1109/WRAP47485.2019.9013736},
  url = {10.1109/WRAP47485.2019.9013736},
  eventtitle = {2019 {{Workshop}} on {{Recent Advances}} in {{Photonics}} ({{WRAP}})}
}
  10. Unraveling Molecular Interactions in Binary Liquid Mixtures with Time-Resolved Thermal-Lens-Spectroscopy. A. K. Rawat, S. Chakraborty, A. K. Mishra, and D. Goswami, Journal of Molecular Liquids 336, 116322 (2021) [Abstract] [PDF] [BibTeX]

    Abstract: Non-contact localized laser heating-based thermal lensing has emerged as a technique for probing the heat transport in liquids. A mode-mismatched dual-beam pump–probe spectroscopic technique was employed to investigate the photothermal response and modes of heat dissipation in methanol and binary mixtures of methanol with polar (water, methanol (MeOH)) and nonpolar (CCl4) solvents. We recorded the time-resolved thermal lens (TL) signal of a probe beam at 780 nm after heat deposition by a 1560 nm pump beam. For pure solvents, the TL signal was found to be approximately one order of magnitude larger for methanol than for water, DMSO, or CCl4, implying that the energy deposition is larger for methanol than for any of the other solvents. Subsequently, binary mixtures were studied where the TL signal increased with an increase in the volume fraction of methanol. All TL signals are shown to have a physical interpretation in terms of heat conduction and convection. In the case of methanol–water, the observed trend can be rationalized in terms of a strong intermolecular interaction. Convective heat transfer is shown to dominate the overall heat transfer in pure methanol and in binary mixtures for all volume fractions where MeOH is in excess of 50%. No convection is observed for very dilute mixtures with a small amount of methanol; in this case, heat conduction is sufficient to reach equilibration. Interestingly, for binary mixtures of methanol with DMSO or water, a decreasing trend is observed in the concentration range between 90% and 100% volume fraction of methanol. We observe also that the TL signal is modified in case of intermolecular interactions forming large clusters of methanol with the cosolvent. In such cases, heat diffusion is affected. Thus, TL can be seen as a sensitive probe for intermolecular interactions as well.

     BibTeX: @article{rawatUnravelingMolecularInteractions2021,
  title = {Unraveling Molecular Interactions in Binary Liquid Mixtures with Time-Resolved Thermal-Lens-Spectroscopy},
  author = {Rawat, Ashwini Kumar and Chakraborty, Subhajit and Mishra, Amit Kumar and Goswami, Debabrata},
  date = {2021-08-15},
  journaltitle = {Journal of Molecular Liquids},
  shortjournal = {Journal of Molecular Liquids},
  volume = {336},
  pages = {116322},
  issn = {0167-7322},
  doi = {10.1016/j.molliq.2021.116322},
  url = {https://www.sciencedirect.com/science/article/pii/S0167732221010461},
  urldate = {2023-07-28}
}