skip to main content

DOE PAGESDOE PAGES

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

Two-dimensional electronic spectroscopy (2DES) is an incisive tool for disentangling excited state energies and dynamics in the condensed phase by directly mapping out the correlation between excitation and emission frequencies as a function of time. Despite its enhanced frequency resolution, the spectral window of detection is limited to the laser bandwidth, which has often hindered the visualization of full electronic energy relaxation pathways spread over the entire visible region. Here, we describe a high-sensitivity, ultrabroadband 2DES apparatus. We report a new combination of a simple and robust setup for increased spectral bandwidth and shot-to-shot detection. We utilize 8-fs supercontinuum pulses generated by gas filamentation spanning the entire visible region (450 – 800 nm), which allows for a simultaneous interrogation of electronic transitions over a 200-nm bandwidth, and an all-reflective interferometric delay system with angled nanopositioner stages achieves interferometric precision in coherence time control without introducing wavelength-dependent dispersion to the ultrabroadband spectrum. To address deterioration of detection sensitivity due to the inherent instability of ultrabroadband sources, we introduce a 5-kHz shot-to-shot, dual chopping acquisition scheme by combining a high-speed line-scan camera and two optical choppers to remove scatter contributions from the signal. Comparison of 2D spectra acquired by shot-to-shot detection andmore » averaged detection shows a 15-fold improvement in the signal-to-noise ratio. In conclusion, this is the first direct quantification of detection sensitivity on a filamentation-based ultrabroadband 2DES apparatus.« less
Authors:
 [1] ;  [1] ; ORCiD logo [1]
  1. Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemistry
Publication Date:
Grant/Contract Number:
SC0001088
Type:
Accepted Manuscript
Journal Name:
Optics Express
Additional Journal Information:
Journal Volume: 25; Journal Issue: 16; Journal ID: ISSN 1094-4087
Publisher:
Optical Society of America (OSA)
Research Org:
Massachusetts Inst. of Tech., Cambridge, MA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1465130