Associate Research Professor in the Department of Chemistry
Dr. Fischer’s research focuses on exploring novel nonlinear optical contrast mechanisms for molecular imaging. Nonlinear optical microscopes can provide non-invasive, high-resolution, 3-dimensional images even in highly scattering environments such as biological tissue.
Established contrast mechanisms, such as two-photon fluorescence or harmonic generation, can image a range of targets (such as autofluorescent markers or some connective tissue structure), but many of the most molecularly specific nonlinear interactions are harder to measure with power levels one might be willing to put on tissue. In order to use these previously inaccessible interactions as structural and molecular image contrasts we are developing ultrafast laser pulse shaping and pulse shape detection methods that dramatically enhance measurement sensitivity. Applications of these microscopy methods range from imaging biological tissue (mapping structure, endogenous tissue markers, or exogenous contrast agents) to characterization of nanomaterials (such as graphene and gold nanoparticles). The molecular contrast mechanisms we originally developed for biomedical imaging also provide pigment-specific signatures for paints used in historic artwork. Recently we have demonstrated that we can noninvasively image paint layers in historic paintings and we are currently developing microscopy techniques for use in art conservation and conservation science.
Advanced Light Imaging and Spectroscopy (ALIS) awarded by (Principal Investigator). 2019 to 2022
OP: Collaborative Research: Multimodal Molecular Spectroscopy and Imaging in Biological Tissue and Historical Artwork awarded by National Science Foundation (Principal Investigator). 2016 to 2019
Improving Melanoma Diagnosis with Pump-Probe Optical Imaging awarded by National Institutes of Health (Researcher). 2013 to 2017
Collaborative Research: Development of Novel Nonlinear Optical Contrast for Artwork Imaging awarded by National Science Foundation (Principal Investigator). 2013 to 2017
Yu, Jin, et al. “Visualization of vermilion degradation using pump-probe microscopy..” Science Advances, vol. 5, no. 6, June 2019. Epmc, doi:10.1126/sciadv.aaw3136. Full Text
Yang, J. K. W., et al. “Design, manufacture, and analysis of photonic materials for historical and modern visual art: Feature issue introduction.” Optical Materials Express, vol. 9, no. 5, May 2019. Scopus, doi:10.1364/OME.9.002128. Full Text
Ju, Kuk-Youn, et al. “Unraveling the molecular nature of melanin changes in metastatic cancer..” Journal of Biomedical Optics, vol. 24, no. 5, Apr. 2019, pp. 051414–051414. Manual, doi:10.1117/1.jbo.24.5.051414. Full Text
Yu, J., et al. “Probing the Spatial Heterogeneity of Carrier Relaxation Dynamics in CH3NH3PbI3 Perovskite Thin Films with Femtosecond Time-Resolved Nonlinear Optical Microscopy.” Advanced Optical Materials, Jan. 2019. Scopus, doi:10.1002/adom.201901185. Full Text
Ju, Kuk-Youn, et al. “Understanding the Role of Aggregation in the Broad Absorption Bands of Eumelanin..” Acs Nano, vol. 12, no. 12, Dec. 2018, pp. 12050–61. Epmc, doi:10.1021/acsnano.8b04905. Full Text
Yu, Jin, et al. “Spectroscopic Differentiation and Microscopic Imaging of Red Organic Pigments Using Optical Pump-Probe Contrast..” Analytical Chemistry, vol. 90, no. 21, Nov. 2018, pp. 12686–91. Epmc, doi:10.1021/acs.analchem.8b02949. Full Text
Liu, Xiaojun, et al. “Enhanced Two-Photon Photochromism in Metasurface Perfect Absorbers..” Nano Letters, vol. 18, no. 10, Oct. 2018, pp. 6181–87. Epmc, doi:10.1021/acs.nanolett.8b02042. Full Text
Stanton, I. N., et al. “Power-Dependent Radiant Flux and Absolute Quantum Yields of Upconversion Nanocrystals under Continuous and Pulsed Excitation.” Journal of Physical Chemistry C, vol. 122, no. 1, Jan. 2018, pp. 252–59. Scopus, doi:10.1021/acs.jpcc.7b11929. Full Text
Wilson, Jesse W., et al. “Comparison of pump-probe and hyperspectral imaging in unstained histology sections of pigmented lesions..” Biomedical Optics Express, vol. 8, no. 8, Aug. 2017, pp. 3882–90. Epmc, doi:10.1364/BOE.8.003882. Full Text
Robles, Francisco E., et al. “Label-Free Imaging of Female Genital Tract Melanocytic Lesions With Pump-Probe Microscopy: A Promising Diagnostic Tool..” J Low Genit Tract Dis, vol. 21, no. 2, Apr. 2017, pp. 137–44. Pubmed, doi:10.1097/LGT.0000000000000290. Full Text
Robles, Francisco E., et al. “Dispersion-based stimulated Raman scattering spectroscopy, holography, and optical coherence tomography (Conference Presentation).” Multiphoton Microscopy in the Biomedical Sciences Xvi, SPIE, 2016. Crossref, doi:10.1117/12.2212875. Full Text
Warren, W. S., et al. “Melanin-targeted nonlinear microscopy for label-free molecular diagnosis and staging.” Optics Infobase Conference Papers, 2016. Scopus, doi:10.1364/TRANSLATIONAL.2016.TTh3B.3. Full Text
Villafana, Tana, et al. “3D chemical imaging of historic artworks and cultural heritage materials.” Abstracts of Papers of the American Chemical Society, vol. 251, AMER CHEMICAL SOC, 2016.
Wilson, J. W., et al. “Real-time digital signal processing in multiphoton and time-resolved microscopy.” Progress in Biomedical Optics and Imaging Proceedings of Spie, vol. 9703, 2016. Scopus, doi:10.1117/12.2218102. Full Text
Villafana, T. E., et al. “Ultrafast pump-probe dynamics of iron oxide based earth pigments for applications to ancient pottery manufacture.” Proceedings of Spie the International Society for Optical Engineering, vol. 9527, 2015. Scopus, doi:10.1117/12.2184758. Full Text
Wilson, J. W., et al. “Separating higher-order nonlinearities in transient absorption microscopy.” Proceedings of Spie the International Society for Optical Engineering, vol. 9584, 2015. Scopus, doi:10.1117/12.2187133. Full Text
Park, J. K., et al. “Femtosecond pulse train shaping for accurate two-photon excited fluorescence measurements.” Laser Science, Ls 2014, 2014.
Samineni, P., et al. “Nonlinear phase contrast imaging in neuronal tissue.” Optics Infobase Conference Papers, 2011.
Warren, W. S. “Tissue imaging with shaped femtosecond laser pulses.” Optics Infobase Conference Papers, 2009.
Gutiérrez-Medina, B., et al. “Observation of the quantum zeno and anti-zeno effects in an unstable system.” Technical Digest Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, Qels 2001, 2001, p. QPD1.1-QPD1.2. Scopus, doi:10.1109/QELS.2001.962243. Full Text
Fischer, Martin, et al. Data from: In vivo pump-probe and multiphoton fluorescence microscopy of melanoma and pigmented lesions in a mouse model. 15 July 2019. Manual, doi:10.7924/r4cc0zp95. Full Text