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.
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
Ju, K-Y, Fischer, MC, and Warren, WS. "Understanding The Role Of Aggregation In The Broad Absorption Bands Of Eumelanin." Acs Nano (November 30, 2018). Full Text
Yu, J, Warren, WS, and Fischer, MC. "Spectroscopic Differentiation and Microscopic Imaging of Red Organic Pigments Using Optical Pump-Probe Contrast." Analytical Chemistry 90.21 (November 2018): 12686-12691. Full Text
Liu, X, Jia, X, Fischer, M, Huang, Z, and Smith, DR. "Enhanced Two-Photon Photochromism in Metasurface Perfect Absorbers." Nano Letters 18.10 (October 2018): 6181-6187. Full Text
Stanton, IN, Ayres, JA, Stecher, JT, Fischer, MC, Scharpf, D, Scheuch, JD, and Therien, MJ. "Power-Dependent Radiant Flux and Absolute Quantum Yields of Upconversion Nanocrystals under Continuous and Pulsed Excitation." Journal of Physical Chemistry C 122.1 (January 11, 2018): 252-259. Full Text
Wilson, JW, Robles, FE, Deb, S, Warren, WS, and Fischer, MC. "Comparison of pump-probe and hyperspectral imaging in unstained histology sections of pigmented lesions." Biomedical Optics Express 8.8 (August 2017): 3882-3890. Full Text
Robles, FE, Deb, S, Fischer, MC, Warren, WS, and Selim, MA. "Label-Free Imaging of Female Genital Tract Melanocytic Lesions With Pump-Probe Microscopy: A Promising Diagnostic Tool." Journal of Lower Genital Tract Disease 21.2 (April 2017): 137-144. Full Text
Robles, FE, Zhou, KC, Fischer, MC, and Warren, WS. "Stimulated Raman scattering spectroscopic optical coherence tomography." Optica 4.2 (February 14, 2017): 243-246. Full Text
Villafana, TE, Delaney, JK, Warren, WS, and Fischer, MC. "High-resolution, three-dimensional imaging of pigments and support in paper and textiles." Journal of Cultural Heritage 20 (July 1, 2016): 583-588. Full Text
Robles, FE, Fischer, MC, and Warren, WS. "Dispersion-based stimulated Raman scattering spectroscopy, holography, and optical coherence tomography." Optics Express 24.1 (January 2016): 485-498. Full Text
Warren, WS, Robles, F, Fischer, M, Wilson, J, Deb, S, Ju, K, and Degan, S. "Melanin-targeted nonlinear microscopy for label-free molecular diagnosis and staging." April 18, 2016. Full Text
Villafana, T, Brown, B, Delaney, J, Fischer, M, Warren, W, and Stranick, S. "3D chemical imaging of historic artworks and cultural heritage materials.": AMER CHEMICAL SOC, March 13, 2016.
Robles, FE, Fischer, MC, and Warren, WS. "Dispersion-based stimulated Raman scattering spectroscopy, holography, and optical coherence tomography (Conference Presentation)." Conference on Multiphoton Microscopy in the Biomedical Sciences XVI. February 14, 2016 - February 16, 2016. San Francisco, CA.: SPIE-INT SOC OPTICAL ENGINEERING, January 1, 2016. Full Text
Wilson, JW, Warren, WS, and Fischer, MC. "Real-time digital signal processing in multiphoton and time-resolved microscopy." January 1, 2016. Full Text
Wilson, JW, Anderson, M, Park, JK, Fischer, MC, and Warren, WS. "Separating higher-order nonlinearities in transient absorption microscopy." SPIE Optical Engineering + Applications.: SPIE, August 26, 2015. Full Text
Villafana, TE, Brown, W, Warren, WS, and Fischer, M. "Ultrafast pump-probe dynamics of iron oxide based earth pigments for applications to ancient pottery manufacture." January 1, 2015. Full Text
Park, JK, Fischer, MC, Susumu, K, Therien, MJ, and Warren, WS. "Femtosecond pulse train shaping for accurate two-photon excited fluorescence measurements." January 1, 2014.
Samineni, P, Fischer, MC, Liu, HC, Yasuda, R, and Warren, WS. "Nonlinear phase contrast imaging in neuronal tissue." January 1, 2011.
Warren, WS. "Tissue imaging with shaped femtosecond laser pulses." January 1, 2009.
Gutiérrez-Medina, B, Fischer, MC, and Raizen, MG. "Observation of the quantum zeno and anti-zeno effects in an unstable system." January 1, 2001. Full Text