Two-Photon Spectroscopy and Microscopy

Two-photon absorption and fluorescence of molecules in solution and cells

Two-photon absorption and fluorescence measure cross-sections, solvent effects and molecular environments, with control through pulse shaping.

Question

How do molecular structure, solvent and excitation pulse shape set the two-photon absorption cross-section and the resulting fluorescence signal?

Technique

The lab measures two-photon absorption and fluorescence with femtosecond pulses, using Z-scan and two-photon fluorescence methods [1]. Experiments cover solvent effects on rhodamine dyes [2], polarization control of single- and two-photon fluorescence [3], and delay-tunable pulse pairs for spatiotemporal control of multiphoton fluorescence microscopy [4]. Two-photon fluorescence also serves as a probe of the environment inside cells [5].

Representative papers

• Two-Photon Cross-Section Measurements Using an Optical Chopper: Z-Scan and Two-Photon Fluorescence, Journal of Physics B, 2009. doi:10/bhffqb
• Polarization Induced Control of Single and Two-Photon Fluorescence, The Journal of Chemical Physics, 2010. doi:10/bdr2kh
• Selective Suppression of Two-Photon Fluorescence in Laser Scanning Microscopy by Ultrafast Pulse-Pair Excitation, Journal of Biomedical Optics, 2010. doi:10/cp9rx2
• Exploring Synergism in Hydrogen-Bonded Binary Solvents through Two-Photon Induced Fluorescence, Journal of Molecular Liquids, 2025. doi:10.1016/j.molliq.2025.127255

Related topics: spatiotemporal control and thermal effects and sensing. Full list of papers here.

Publications

1. Deciphering Micro-Polarity inside the Endoplasmic Reticulum Using a Two-Photon Active Solvatofluorochromic Probe. K. Pal, I. Samanta, R. Kumar Gupta, D. Goswami, and A. Lal Koner, Chemical Communications 54(75), 10590–10593 (2018)

   BibTeX: @article{palDecipheringMicropolarityEndoplasmic2018,
     title = {Deciphering Micro-Polarity inside the Endoplasmic Reticulum Using a Two-Photon Active Solvatofluorochromic Probe},
     author = {Pal, Kaushik and Samanta, Indranil and Kumar~Gupta, Rahul and Goswami, Debabrata and Lal~Koner, Apurba},
     year = {2018},
     journal = {Chemical Communications},
     volume = {54},
     number = {75},
     pages = {10590--10593},
     doi = {10/gf5mqx},
     urldate = {2019-08-01},
     langid = {english},
     annotation = {GSCC: 0000030 \\
     26 citations (Crossref) [2024-05-28]\\
     00003}
   }
   

2. Spatiotemporal Control of Degenerate Multiphoton Fluorescence Microscopy with Delay-Tunable Femtosecond Pulse Pairs. D. Das, I. Bhattacharyya, and D. Goswami, Chemical Physics Letters 657, 72–77 (2016)

   BibTeX: @article{dasSpatiotemporalControlDegenerate2016,
     title = {Spatiotemporal Control of Degenerate Multiphoton Fluorescence Microscopy with Delay-Tunable Femtosecond Pulse Pairs},
     author = {Das, Dhiman and Bhattacharyya, Indrajit and Goswami, Debabrata},
     year = {2016},
     month = jul,
     journal = {Chemical Physics Letters},
     volume = {657},
     pages = {72--77},
     issn = {0009-2614},
     doi = {10/f84rwd},
     urldate = {2019-08-01},
     annotation = {GSCC: 0000003 \\
     3 citations (Crossref) [2024-05-28]\\
     00000}
   }
   

3. Polarization Induced Control of Single and Two-Photon Fluorescence. A. Nag and D. Goswami, The Journal of Chemical Physics 132(15), 154508 (2010)

   BibTeX: @article{nagPolarizationInducedControl2010,
     title = {Polarization Induced Control of Single and Two-Photon Fluorescence},
     author = {Nag, Amit and Goswami, Debabrata},
     year = {2010},
     month = apr,
     journal = {The Journal of Chemical Physics},
     volume = {132},
     number = {15},
     pages = {154508},
     issn = {0021-9606},
     doi = {10/bdr2kh},
     urldate = {2019-08-14},
     annotation = {GSCC: 0000027 \\
     22 citations (Crossref) [2024-05-28]\\
     00022}
   }
   

4. Solvent Effect on Two-Photon Absorption and Fluorescence of Rhodamine Dyes. A. Nag and D. Goswami, Journal of Photochemistry and Photobiology A: Chemistry 206(2), 188–197 (2009)

   BibTeX: @article{nagSolventEffectTwophoton2009,
     title = {Solvent Effect on Two-Photon Absorption and Fluorescence of Rhodamine Dyes},
     author = {Nag, Amit and Goswami, Debabrata},
     year = {2009},
     month = aug,
     journal = {Journal of Photochemistry and Photobiology A: Chemistry},
     volume = {206},
     number = {2},
     pages = {188--197},
     issn = {1010-6030},
     doi = {10/c4zdx8},
     urldate = {2019-08-14},
     annotation = {GSCC: 0000110 \\
     83 citations (Crossref) [2024-05-28]\\
     00063}
   }
   

5. Two-Photon Cross-Section Measurements Using an Optical Chopper: Z-Scan and Two-Photon Fluorescence Schemes. A. Nag, A. K. De, and D. Goswami, Journal of Physics B: Atomic, Molecular and Optical Physics 42(6), 065103 (2009)

   BibTeX: @article{nagTwophotonCrosssectionMeasurements2009,
     title = {Two-Photon Cross-Section Measurements Using an Optical Chopper: Z-Scan and Two-Photon Fluorescence Schemes},
     shorttitle = {Two-Photon Cross-Section Measurements Using an Optical Chopper},
     author = {Nag, Amit and De, Arijit Kumar and Goswami, Debabrata},
     year = {2009},
     month = mar,
     journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
     volume = {42},
     number = {6},
     pages = {065103},
     issn = {0953-4075, 1361-6455},
     doi = {10/bhffqb},
     urldate = {2018-12-10},
     annotation = {GSCC: 0000049 \\
     39 citations (Crossref) [2024-05-28]\\
     00000}
   }