Krishnandu Makhal

09 March 2026

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Education / Work History

• Postdoctoral Research Associate, University of Michigan (2017-present)
• Ph.D. Scholar, IIT Kanpur (2010-2017)
• M.Sc., Banaras Hindu University (2008-2010)

Thesis Abstract

Third Order Optical Nonlinearities and Ultra-fast Dynamics at Visible and Near-IT Wavelengths

The central theme of this thesis is twofold: One is to investigate third-order optical nonlinearities of conjugated dye molecules (organic chromophores) in the condensed phase i.e. in organic and inorganic solvents by means of Z-scan studies. These molecules absorb in visible and/or near-infra-red (NIR) wavelengths. In the present study laser pulses with widths ranging from a few hundreds of nanoseconds to tens of femtoseconds are employed with tunable wavelengths spanning the visible to NIR regions. The second theme of this thesis is to study the ultrafast dynamics of the aforesaid chromophores with femtosecond pulses employing pump-probe spectroscopy. Several subclasses, such as, degenerate and non-degenerate pump-probe technique, UV-vis pump and supercontinuum probe technique in addition to transient absorption, time correlated single photon counting (TCSPC) techniques are employed to monitor and explore the relaxation process and pathways. To understand the effect of molecular geometry and the possible effects of molecular structure due to electron delocalization on third-order nonlinearity, full geometry optimization has also been carried out using time dependent density functional theory (TDDFT) with the help of Gaussian09 software package. This combined experimental and theoretical investigations resulted in various new material properties and their ultrafast relaxation pathways, which were never explored earlier for the molecules studied. These studies also open up new applications of the NIR-absorbing dyes in the visible region at non-resonant excitations.

Research Topic / Interest

Nonlinear Spectroscopy and Ultrafast Optics. My research is based on Intense Light matter interaction and the consequences which follow after it. Trying to explain the nonlinear phenomena through Experiments like nonlinear Raman scattering, Three and four wave mixing, SHG, Optical Kerr Effect and magneto optical Kerr effect Spectroscopy. Exploring the Magnetization at Optical frequencies in dielectrics through Magneto-electric interactions experimentally.

Activities and Societies: My dissertation was on Third order nonlinearities and dynamics in visible and near infrared wavelengths. Carried my experiments using home built Pump Probe setup, Transient Absorption Spectroscopy, Two photon absorption and fluorescence spectroscopy and with Z scan experiments. Invested efforts on newly synthesized chromophores and on dielectrics.Activities and Societies: My dissertation was on Third order nonlinearities and dynamics in visible and near infrared wavelengths. Carried my experiments using home built Pump Probe setup, Transient Absorption Spectroscopy, Two photon absorption and fluorescence spectroscopy and with Z scan experiments. Invested efforts on newly synthesized chromophores and on dielectrics.

Publications

These include only those published in our lab.

1. Excited State Absorption and Relaxation Dynamics in a Series of Heptamethine Dyes under Femtosecond and Nanosecond Excitations. K. Makhal, S. Maurya, and D. Goswami, Physica Scripta 94(9), 095501 (2019) [BibTeX]

    BibTeX: @article{makhalExcitedStateAbsorption2019,
     title = {Excited State Absorption and Relaxation Dynamics in a Series of Heptamethine Dyes under Femtosecond and Nanosecond Excitations},
     author = {Makhal, Krishnandu and Maurya, Sidharth and Goswami, Debabrata},
     year = {2019},
     month = jun,
     journal = {Physica Scripta},
     volume = {94},
     number = {9},
     pages = {095501},
     issn = {1402-4896},
     doi = {10/gf5mpz},
     urldate = {2019-08-01},
     langid = {english},
     annotation = {GSCC: 0000005 \\
     5 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

2. Extracting Third Order Optical Nonlinearities of Mn(III)-Phthalocyanine Chloride Using High Repetition Rate Femtosecond Pulses. K. Makhal, P. Mathur, S. Maurya, and D. Goswami, Journal of Applied Physics 121(5), 053103 (2017) [BibTeX]

    BibTeX: @article{makhalExtractingThirdOrder2017,
     title = {Extracting Third Order Optical Nonlinearities of {{Mn}}({{III}})-{{Phthalocyanine}} Chloride Using High Repetition Rate Femtosecond Pulses},
     author = {Makhal, Krishnandu and Mathur, Paresh and Maurya, Sidharth and Goswami, Debabrata},
     year = {2017},
     month = feb,
     journal = {Journal of Applied Physics},
     volume = {121},
     number = {5},
     pages = {053103},
     issn = {0021-8979},
     doi = {10/gf5mrh},
     urldate = {2019-08-01},
     annotation = {GSCC: 0000012 \\
     12 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

3. pH Effect on Two-Photon Cross Section of Highly Fluorescent Dyes Using Femtosecond Two-Photon Induced Fluorescence. K. Makhal and D. Goswami, Journal of Fluorescence 27(1), 339–356 (2017) [BibTeX]

    BibTeX: @article{makhalPHEffectTwoPhoton2017,
     title = {{{pH Effect}} on {{Two-Photon Cross Section}} of {{Highly Fluorescent Dyes Using Femtosecond Two-Photon Induced Fluorescence}}},
     author = {Makhal, Krishnandu and Goswami, Debabrata},
     year = {2017},
     month = jan,
     journal = {Journal of Fluorescence},
     volume = {27},
     number = {1},
     pages = {339--356},
     issn = {1573-4994},
     doi = {10/f9rpw6},
     urldate = {2019-08-01},
     langid = {english},
     annotation = {GSCC: 0000004 \\
     3 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

4. Reverse Saturable Absorption Followed by Anomalous Saturable Absorption in Rhodamine-700. K. Makhal, S. Maurya, and D. Goswami, in 13th International Conference on Fiber Optics and Photonics (OSA, 2016), p. Tu5D.2 [BibTeX]

    BibTeX: @inproceedings{makhalReverseSaturableAbsorption2016,
     title = {Reverse {{Saturable Absorption}} Followed by {{Anomalous Saturable Absorption}} in {{Rhodamine-700}}},
     booktitle = {13th {{International Conference}} on {{Fiber Optics}} and {{Photonics}}},
     author = {Makhal, Krishnandu and Maurya, Sidharth and Goswami, Debabrata},
     year = {2016},
     pages = {Tu5D.2},
     publisher = {OSA},
     address = {Kharagpur},
     doi = {10/gf5mrp},
     urldate = {2019-08-01},
     isbn = {978-1-943580-22-4},
     langid = {english},
     annotation = {GSCC: 0000000 \\
     0 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

5. Third-Order Nonlinear Optical Response and Ultrafast Dynamics of Tetraoxa[22]Porphyrin(2.1.2.1)s. K. Makhal, S. Arora, P. Kaur, D. Goswami, and K. Singh, Journal of Materials Chemistry C 4(40), 9445–9453 (2016) [BibTeX]

    BibTeX: @article{makhalThirdorderNonlinearOptical2016,
     title = {Third-Order Nonlinear Optical Response and Ultrafast Dynamics of Tetraoxa[22]Porphyrin(2.1.2.1)s},
     author = {Makhal, Krishnandu and Arora, Shafali and Kaur, Paramjit and Goswami, Debabrata and Singh, Kamaljit},
     year = {2016},
     journal = {Journal of Materials Chemistry C},
     volume = {4},
     number = {40},
     pages = {9445--9453},
     doi = {10/gf5mr7},
     urldate = {2019-08-01},
     langid = {english},
     annotation = {GSCC: 0000026 \\
     22 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

6. Excited State Absorption and Relaxation Dynamics in a Series of Heptamethine Dyes under Femtosecond and Nanosecond Excitations. K. Makhal, S. Maurya, and D. Goswami, Physica Scripta 94(9), 095501 (2019) [BibTeX]

    BibTeX: @article{makhalExcitedStateAbsorption2020,
     title = {Excited State Absorption and Relaxation Dynamics in a Series of Heptamethine Dyes under Femtosecond and Nanosecond Excitations},
     author = {Makhal, Krishnandu and Maurya, Sidharth and Goswami, Debabrata},
     year = {2019},
     month = jun,
     journal = {Physica Scripta},
     volume = {94},
     number = {9},
     pages = {095501},
     issn = {1402-4896},
     doi = {10/gf5mpz},
     urldate = {2019-08-01},
     langid = {english},
     annotation = {GSCC: 0000005 \\
     5 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

7. Extracting Third Order Optical Nonlinearities of Mn(III)-Phthalocyanine Chloride Using High Repetition Rate Femtosecond Pulses. K. Makhal, P. Mathur, S. Maurya, and D. Goswami, Journal of Applied Physics 121(5), 053103 (2017) [BibTeX]

    BibTeX: @article{makhalExtractingThirdOrder2018,
     title = {Extracting Third Order Optical Nonlinearities of {{Mn}}({{III}})-{{Phthalocyanine}} Chloride Using High Repetition Rate Femtosecond Pulses},
     author = {Makhal, Krishnandu and Mathur, Paresh and Maurya, Sidharth and Goswami, Debabrata},
     year = {2017},
     month = feb,
     journal = {Journal of Applied Physics},
     volume = {121},
     number = {5},
     pages = {053103},
     issn = {0021-8979},
     doi = {10/gf5mrh},
     urldate = {2019-08-01},
     annotation = {GSCC: 0000012 \\
     12 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

8. pH Effect on Two-Photon Cross Section of Highly Fluorescent Dyes Using Femtosecond Two-Photon Induced Fluorescence. K. Makhal and D. Goswami, Journal of Fluorescence 27(1), 339–356 (2017) [BibTeX]

    BibTeX: @article{makhalPHEffectTwoPhoton2018,
     title = {{{pH Effect}} on {{Two-Photon Cross Section}} of {{Highly Fluorescent Dyes Using Femtosecond Two-Photon Induced Fluorescence}}},
     author = {Makhal, Krishnandu and Goswami, Debabrata},
     year = {2017},
     month = jan,
     journal = {Journal of Fluorescence},
     volume = {27},
     number = {1},
     pages = {339--356},
     issn = {1573-4994},
     doi = {10/f9rpw6},
     urldate = {2019-08-01},
     langid = {english},
     annotation = {GSCC: 0000004 \\
     3 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

9. Reverse Saturable Absorption Followed by Anomalous Saturable Absorption in Rhodamine-700. K. Makhal, S. Maurya, and D. Goswami, in 13th International Conference on Fiber Optics and Photonics (OSA, 2016), p. Tu5D.2 [BibTeX]

    BibTeX: @inproceedings{makhalReverseSaturableAbsorption2017,
     title = {Reverse {{Saturable Absorption}} Followed by {{Anomalous Saturable Absorption}} in {{Rhodamine-700}}},
     booktitle = {13th {{International Conference}} on {{Fiber Optics}} and {{Photonics}}},
     author = {Makhal, Krishnandu and Maurya, Sidharth and Goswami, Debabrata},
     year = {2016},
     pages = {Tu5D.2},
     publisher = {OSA},
     address = {Kharagpur},
     doi = {10/gf5mrp},
     urldate = {2019-08-01},
     isbn = {978-1-943580-22-4},
     langid = {english},
     annotation = {GSCC: 0000000 \\
     0 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

10. Third-Order Nonlinear Optical Response and Ultrafast Dynamics of Tetraoxa[22]Porphyrin(2.1.2.1)s. K. Makhal, S. Arora, P. Kaur, D. Goswami, and K. Singh, Journal of Materials Chemistry C 4(40), 9445–9453 (2016) [BibTeX]

     BibTeX: @article{makhalThirdorderNonlinearOptical2017,
      title = {Third-Order Nonlinear Optical Response and Ultrafast Dynamics of Tetraoxa[22]Porphyrin(2.1.2.1)s},
      author = {Makhal, Krishnandu and Arora, Shafali and Kaur, Paramjit and Goswami, Debabrata and Singh, Kamaljit},
      year = {2016},
      journal = {Journal of Materials Chemistry C},
      volume = {4},
      number = {40},
      pages = {9445--9453},
      doi = {10/gf5mr7},
      urldate = {2019-08-01},
      langid = {english},
      annotation = {GSCC: 0000026 \\
      22 citations (Crossref) [2024-05-28]\\
      00000}
    }