Associate Professor
Research
The Calhoun lab specializes in the application, advancement, and invention of nonlinear microscopy and spectroscopy techniques for the study of a variety of systems from small molecule antibiotics to nanoparticles. The overarching goal in all of our work is to understand the role of environmental effects by probing electronic excited states with a specific focus on imaging dynamic interfaces. To this end we are employing techniques such as transient absorption microscopy, second harmonic generation spectroscopy and electronic sum frequency generation microspectroscopy to a wide array of systems including the study of drug-membrane interactions and nanoparticle surfaces.
To learn more, visit our group website at https://calhoun.utk.edu/
Education
Post-Doc, Lewis-Sigler Institute for Integrative Genomics, Princeton University
PhD, Chemistry from UC Berkeley
BS, Chemistry from Iowa State University
Publications
Total Internal Reflection Transient Absorption Microscopy: An Online Detection Method for Microfluidics
B. A. Colon, M. R. Hassan, A. Saleheen, C. A. Baker, and T. R. Calhoun
J. Phys. Chem. A 124, 4160 (2020)
(part of the Time-Resolved Microscopy Virtual Special Issue)
Second Harmonic Generation Spectroscopy of Membrane Probe Dynamics in Gram-Positive Bacteria
L. N. Miller, W. T. Brewer, J. D. Williams, E. M. Fozo, and T. R. Calhoun
Biophys. J. 117, 1419 (2019)
Energetics at the Surface: Direct Optical Mapping of Bulk and Interfacial Electronic Structure in CdSe Quantum Dots using Broadband Electronic Sum Frequency Generation Microspectroscopy
B. R. Watson, B. Doughty, and T. R. Calhoun
Nano Lett. 19, 6157 (2019)
A new approach to vibrational sum frequency generation spectroscopy using near infrared pulse shaping
A. U. Chowdhury, B. R. Watson, Y.-Z. Ma, R. L. Sacci, D. A. Lutterman, T. R. Calhoun, and B. Doughty
Rev. Sci. Instrum. 90, 033106 (2019)
Probing ligand removal and ordering at quantum dot surfaces using vibrational sum frequency generation spectroscopy
B. R Watson, Y.-Z. Ma, J. F. Cahill, B. Doughty and T. R. Calhoun
J. Colloid. Interface Sci. 537, 389 (2019)
Chemical nature of ferroelastic twin domains in CH3NH3PbI3 perovskite
Y. Liu, L. Collins, R. Proksch, S. Kim, B. R. Watson, B. Doughty, T. R. Calhoun, M. Ahmadi, A. V. Ievlev, S. Jesse, S. T. Retterer, A. Belianinov, K. Xiao, J. Huang, B. G. Sumpter, S. V. Kalinin, B. Hu, and O. S. Ovchinnikova
Nat. Mater. 11, 1013 (2018)
Shedding light on surface effects: nonlinear probes of complex materials
B. R. Watson, B. Doughty, and T. R. Calhoun
Proc. SPIE 10638, Ultrafast Bandgap Photonics III (2018)
Flexible approach to vibrational sum-frequency generation using shaped near-infrared light
A. U. Chowdhury, F. Liu, B. R. Watson, R. Ashkar, J. Katsaras, C. P. Collier, D. A. Lutterman, Y.-Z. Ma, T. R. Calhoun, and B. Doughty
Opt. Lett. 43, 2038 (2018)
Compressed supercontinuum probe for transient absorption microscopy
K. Higgins and T. R. Calhoun
Opt. Lett. 43, 1750 (2018)
Elucidation of Perovskite Film Micro-Orientations using Two-Photon Total Internal Reflectance Fluorescence Microscopy
B. R. Watson, B. Yang, K. Xiao, Y.-Z. Ma, B. Doughty, and T. R. Calhoun
J. Phys. Chem. Lett. 6, 3283 (2015)