Coherent Data Acquisition Expedited by Collection in Arbitrary Time Directions

MultiDimensional Coherent Optical Photocurrent Spectroscopy ($MDCOPS$) is an experiment that allows for the acquisition of one-dimensional spectra in any arbitrary time direction in the $t$-$\tau$ plane. According to the Projection Slice Theorem of Fourier Transforms, a projection of a MultiDimensional Coherent Spectroscopy ($MDCS$) spectrum onto any arbitrary axis in the $\omega_t$-$\omega_{\tau}$ plane can be acquired by simply taking a one-dimensional spectrum of the four-wave mixing signal while moving both the $t$ and $\tau$ stages concurrently. Conventional $MDCS$ experiments are limited, by their signal detection, to collecting an entire spectrum and taking slices of the resulting data to look at resonance lineshapes. Using the $MDCOPS$ experiment, with smart choice of the direction of data collection, allows direct observation of material properties such as the homogeneous and inhomogeneous linewidths of a resonance, off-diagonal coherence peaks, and population decay peaks with far fewer data points necessary than an entire $MDCS$ spectrum.