Experimental Implementations of Two-Dimensional Fourier Transform Electronic Spectroscopy

Abstract

Two-dimensional electronic spectroscopy (2DES) reveals connections between an optical excitation at a given frequency and the signals it creates over a wide range of frequencies. These connections, manifested as cross-peak locations and their lineshapes, reflect the underlying electronic and vibrational structure of the system under study. How these spectroscopic signatures evolve in time reveals the system dynamics and provides a detailed picture of coherent and incoherent processes. 2DES is rapidly maturing and has already found numerous applications, including studies of photosynthetic energy transfer and photochemical reactions and many-body interactions in nanostructured materials. Many systems of interest contain electronic transitions spanning the ultraviolet to the near infrared and beyond. Most 2DES measurements to date have explored a relatively small frequency range. We discuss the challenges of implementing 2DES and compare and contrast different approaches in terms of their information content, ease of implementation, and potential for broadband measurements.

Ultrabroadband 2D electronic spectroscopy with high-speed, shot-to-shot detection

“…Since the first demonstration of 2DES technique two decades ago, [16,17] various experimental implementations are actively being developed and examined towards enhanced phase stability, a broader spectral window, and faster data acquisition with improved sensitivity [18]. While early instrumental developments in 2DES were centered on achieving interferometric time precision and phase stability, [19][20][21][22] there has recently been a growing interest in the generation of broader excitation sources and development of methods for data acquisition and processing [23][24][25].…”

Optimizing sparse sampling for 2D electronic spectroscopy

“…20 A detailed comparison of various experimental 2D spectroscopy approaches can be found in a recent review. 21 Multidimensional spectroscopy in general requires multidimensional scanning of parameters such as time delays or phases. While single-shot techniques have been developed, 22,23 the question remains whether the amount of data to be acquired can be reduced while retaining the essential information content of the resulting 2D spectrum.…”

Probing polaron excitation spectra in organic semiconductors by photoinduced-absorption-detected two-dimensional coherent spectroscopy

“…Multidimensional electronic spectroscopy (ES) developed in analogy to the counterpart of nuclear magnetic resonance has become a powerful tool to study the electronic dynamics of macromolecular systems [1][2][3]. By probing nonlinear optical responses and spreading them along two time/frequency axes, such spectroscopic experiments reveal transient correlations between specific electronic transitions with femtosecond temporal resolution [4,5].…”

“…By probing nonlinear optical responses and spreading them along two time/frequency axes, such spectroscopic experiments reveal transient correlations between specific electronic transitions with femtosecond temporal resolution [4,5]. Usual implementations of 2D ES rely upon optical wavevector matching to measure a thirdorder mesoscopic polarization response [2].In this work, we focus upon the two-dimensional photoexcitation spectroscopy (2D PES), as a variant of 2D ES techniques, in which the detected nonlinear optical signals rely on the fourth-order excited-state population. According to the final population of interest, one can probe the excitation spectral signals in forms of photoluminescence (PL) [6][7][8] or photocurrent (PC) [9][10][11], for example.…”

“…Regarding the 2D ES implementations, the welldeveloped four-wave mixing (FWM) approach is a con- * hli39@uh.edu † carlos.silva@umontreal.ca ‡ bittner@uh.edu ventional technique in which non-collinear optical pulses are often employed [2]. Owing to advances in ultrafast optics, one can prepare precise sequences of pulses with well-defined pulse envelopes, wave-vector directions, time intervals, and relative phases.…”