Noisy Light Spectroscopy Darin J. Ulness Department of Chemistry Concordia College, Moorhead, MN

Noisy Light Spectroscopy What is noisy light? History Theory Experiment Applications and results Context The future of noisy light spectroscopy

What is Noisy Light? Time resolution on Broadband the order of the correlation time, tc Broadband Phase incoherent Quasi continuous wave Noisy Light Spectrum Frequency

What is Noisy Light? Ultrashort pulse Time resolution on the order of the pulse width Broadband Phase incoherent Quasi continuous wave Phase locked Coherent Short Pulse Spectrum Frequency Time

What is Noisy Light? Phase Incoherent unlocked Time Noisy Light Spectrum Frequency Time

Color locked! What is Noisy Light? Phase Incoherent unlocked Time Noisy Light Spectrum Frequency Time

What is Noisy Light? Beam B Time

What is Noisy Light? Beam B Beam B’ Time

What is Noisy Light? t Beam B Beam B’ Time

What is Noisy Light? t Compare t with tc Beam B Beam B’ Time

History FTC diagrams invented Morita, Asaka, Hartmann develop the photon echo Higher dimensional spectroscopy Dugan develops Spectrally resolved CARS Exciton quantum beats 1983 1986 1996 1998 2014 Most noisy light papers published between 1986 and 1996. Many counter parts to short pulse methods. Noisy light focused on application of CARS. Very few groups working with noisy light from 1996 on.

Noisy Light Spectroscopy Foundations of Noisy Light Noisy Light Spectroscopy Optical coherence theory Perturbation theory: Density operator

P= c E Nonlinear Spectroscopy P(t) = P(1) + P(2) + P(3) … Signal Material Light field P= c E Perturbation series approximation P(t) = P(1) + P(2) + P(3) … P(1) = c (1)E, P(2) = c (2)EE, P(3) = c (3)EEE

CARS Coherent Anti-Stokes Raman Scattering wCARS -w2 w1-w2= wR w1 wCARS= w1 +wR time

Bichromophoric Model P(t) (3) a Noisy light < > P(s) (3)* b

Theoretical Challenges Complicated Mathematics Complicated Physical Interpretation Difficulty The cw nature requires all field action permutations. The light is always on. The proper treatment of the noise cross-correlates chromophores.

FTC Diagram Analysis Physics easy hard hard Set of evaluated intensity level terms Messy integration and algebra Set of intensity level terms (pre-evaluated) Set of FTC diagrams Construction Rules Evaluation Rules easy hard Physics hard

a b FTC Diagram Analysis a b a b P(t,{ti}) P(s,{si}) P(t,{ti}) <BB’B’*B*> = <BB’*><B’B*> + <BB*><B’B’*> time time a b a b P(t,{ti}) P(s,{si}) P(t,{ti}) P(s,{si})

FTC Diagram Analysis a b P(t,{ti}) P(s,{si}) arrow segments: t-dependent correlation line segments: t-independent correlation

Indirect Correlation time a b t t

Indirect Correlation time a b t t Dynamics on a are probed!

I(2)CARS: Experiment Signal is dispersed onto the CCD Monochromator Narrowband Source Broadband Lens Sample Interferometer t B B’ M I(2)CARS Computer CCD Signal is dispersed onto the CCD Entire Spectrum is taken at each delay 2D data set: the Spectrogram

I(2)CARS: Experiment Great sensitivity to vibrational shifts and dephasing changes Ring breathing mode of benzene in hexane

I(2)CARS: Data Processing Fourier Transformation X-Marginal

I(2)CARS: Hydrogen Bonding Neat Pyridine FT Pyridine/ Water Xw= 0.55

I(2)CARS: Hydrogen Bonding

I(2)CARS: Hydrogen Bonding Network model Etc. Thermalized distribution model Fileti, E.E.; Countinho, K.; Malaspina, T.; Canuto, S. Phys. Rev. E. 2003, 67, 061504.

Halogen Bonding Electropositve s-hole Electroneutral “ring” Test Charge Electroneutral “ring” Electronegative “belt”

I(2)CARS: Halogen Bonding

Exciton Quantum Beats

Exciton Quantum Beats

Future of Noisy Light Spectroscopy Information Processing I(4)2DES Theory I(4)2DES Experiment I(2)CARS Experiment Information Processing Dendritic Integration Indirect correlation in systems Applied Mathematics Group Theory Graph Theory Braid Theory

Acknowledgements Students Funding Other Group Members Theory Jahan Dawlaty Dan Biebighauser John Gregiore Duffy Turner Kurt Haag Issac Heath Carena Daniels Method Development Pye Phyo Aung Tanner Schulz Lindsay Weisel Krista Cosert Perrie Cole Alex Harsh Britt Berger Zach Johnson Thao Ta Hydrogen/Halogen bonding Eric Berg Jeff Eliason Diane Moliva Jason Olson Scott Flancher Danny Green Exciton Beats Erika Sutor Becca Hendrickson Meghan Knudtzon Dylan Howie Bobby Spoja Funding Other Group Members NSF CAREER Grant CHE-0341087 Henry Dreyfus Teacher/Scholar program Concordia Chemistry Research Fund Dr. Mark Gealy, Department of Physics Dr. Eric Booth, Post-doctoral researcher Dr. Haiyan Fan, Post-doctoral researcher