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authorBlaise Thompson <blaise@untzag.com>2018-04-07 18:20:04 -0500
committerBlaise Thompson <blaise@untzag.com>2018-04-07 18:20:04 -0500
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@@ -19,39 +19,42 @@
Coherent multidimensional spectroscopy (CMDS) is a family of experimental strategies capable of
providing unique insights into microscopic material physics. %
-It is similar to the more familiar [NMR EXPERIMENTS], although the implementation is different due
-to differences between the behavior of nuclear spin states (probed by NMR) and electronic and
-vibrational states (probed by CMDS). %
+It is similar to more familiar multidimensional NMR experiments \cite{ZhaoWei2000b,
+ PakoulevAndreiV2006a}, although the implementation is different due to differences between the
+behavior of nuclear spin states (probed by NMR) and electronic and vibrational states (probed by
+CMDS). %
CMDS can resolve couplings between states, and can decongest spectra by taking advantage of
dimensionality and selection rules. %
With the advent of ultrafast lasers, CMDS can resolve dynamics in excited states and the coupling
-between them. %
+between them. \cite{RentzepisPM1970a} %
CMDS is most often performed in the time domain, where multiple broadband pulses are scanned in
-time to collect a multidimensional interferogram. [CITE] %
-This technique is fast and robust---it has even been performed on a single shot. [CITE] %
+time to collect a multidimensional interferogram. \cite{MukamelShaul2009a, GallagherSarahM1998a} %
+This technique is fast and robust---it has even been performed on a single shot.
+\cite{HarelElad2010a} %
However time-domain CMDS has some fundamental limitations:
\begin{ditemize}
\item The frequency bandwidth must be contained within the excitation pulse---and ultrabroadband
- pulses are hard to make and control. [CITE JONAS]
+ pulses are hard to make and control. \cite{SpencerAustinP2015a} %
\item A phase-locked local oscillator is required, and preparing a local oscillator for experiments
with unique output colors is challenging.
\end{ditemize}
Scientists in the time-domain CMDS community are taking both of these challenges head-on, pushing
-the envelope in excitation pulse bandwidth [CITE 2DWL] and performing two-stage experiments in
-which excitation pulses are used to generate a local oscillator in non-resonant media [CITE
-ZANNI]. %
+the envelope in excitation pulse bandwidth \cite{KearnsNicholasM2017a} and performing two-stage
+experiments in which excitation pulses are used to generate a local oscillator in non-resonant
+media \cite{XiongWei2011a}. %
An alternative strategy is frequency domain ``multi-resonant'' CMDS (MR-CMDS). %
Rather than using a single broadband excitation pulse, MR-CMDS employs a relatively narrow-band
source with a tunable frequency. %
-Motorized optical parametric amplifiers (OPAs) are typically used to provide this tunability. %
+Motorized optical parametric amplifiers (OPAs) are typically used to provide this tunability.
+\cite{CerulloGiulio2003a} %
In MR-CMDS, frequency axes are resolved directly by scanning these motorized OPAs. %
This process is time intensive, and it can be challenging to ensure that the OPAs are well
calibrated and that the experiment is not affected by the motion of crystals and other optics
inside these automated OPAs. %
Despite these challenges, MR-CMDS is an incredibly flexible strategy that can be a very powerful
-analytical tool. %
+analytical tool. \cite{PakoulevAndreiV2009a} %
Because MR-CMDS does not require that all frequencies be contained within one broadband source,
there is no theoretical limit to the frequency range that can be resolved in this way. %
MR-CMDS can be homodyne-detected, so experiments with unique output colors are much more
@@ -59,12 +62,10 @@ accessible. %
Finally, because the components are more self-contained, MR-CMDS instruments tend to be more
flexible in the kinds of experiments that they can perform. %
-% TODO: boilerplate about the kinds of things that make up an MR-CMDS instrument... OPAs, delays...
-
This dissertation contains several projects undertaken to improve the reliability and accessibility
of MR-CMDS. %
While MR-CMDS will never be a single-shot experiment, there are many improvements that can improve
-data collection speed. % JCW- NOT SO SURE IT CAN'T BE SINGLE SHOT
+data collection speed. % JCW: NOT SO SURE IT CAN'T BE SINGLE SHOT
Necessary calibration, especially OPA calibration, can be made robust and fully automatic. %
Common artifacts can be addressed through relatively simple modifications in hardware and
software. %
@@ -135,11 +136,13 @@ decreased acquisition times by up to two orders of magnitude. %
Like any analytical technique, MR-CMDS is subject to artifacts: features of the data that are
caused by instrumental imperfections or limitations, and do not reflect the intrinsic material
response that is of interest. %
-% HOW THE EXPERIMENT WAS DONE, NOT WHAT IT IS HOPING TO MEASURE
-For example, M-factors are ... [CITE] and [CITE JONAS PULSE PROPAGATION]. %
+% JCW: HOW THE EXPERIMENT WAS DONE, NOT WHAT IT IS HOPING TO MEASURE
+For example, consider absorptive effects \cite{CarlsonRogerJohn1989a}, pulse effects
+\cite{SpencerAustinP2015a}, and window contributions \cite{MurdochKiethM2000a}: all well-known
+artifacts in CMDS. %
Since MR-CMDS is a very active experiment, with many moving motors, an active approach to artifact
correction is particularly appropriate. %
-\autoref{cha:act} describes strategies for implementing such corrections. %
+Chapter \ref{cha:act} describes strategies for implementing such corrections. %
Spectral delay correction can be applied to account for the fact that not all output colors arrive
at the same time. %
Dual chopping can correct for scatter and other unwanted processes, ensuring that the observed
@@ -157,15 +160,15 @@ The impulsive limit is particularly well suited for describing time domain exper
In the driven limit, pulses are narrow in frequency and long in time compared to material
response. %
Resonant responses are driven, like a jello dessert sitting on a washing machine. %
-The expected spectrum in both of these limits can be computed analytically. [CITE] %
+The expected spectrum in both of these limits can be computed analytically. %
Things get more complicated in the mixed domain, where pulses have similar bandwidth as the
material response. %
Experiments in this domain are a practical necessity as CMDS addresses systems with very fast
-dephasing times [CITE]. %
-% TODO: cite smallwood and similar somewhere around here
+dephasing times. \cite{SmallwoodChristopherL2016a, PerlikVaclav2017a} %
At the same time, the marginal resolution in frequency \emph{and} time that the mixed domain
-possess promises huge potential in pathway resolution and decongestion. [CITE JOHN OR ANDREI] %
-\autoref{cha:mix} describes the pitfalls and opportunities contained in the mixed domain
+possess promises huge potential in pathway resolution and decongestion.
+\cite{PakoulevAndreiV2009a} %
+Chapter \ref{cha:mix} describes the pitfalls and opportunities contained in the mixed domain
approach. %
An intuitive description of mixed-domain experiments is given. %
False signatures of material correlation are discussed, and strategies for resolving true material