Denk O, Zheng K, Zigmantas D, Žídek K. Compressive imaging of transient absorption dynamics on the femtosecond timescale.
Opt Express 2019;
27:10234-10246. [PMID:
31045167 DOI:
10.1364/oe.27.010234]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/02/2019] [Indexed: 06/09/2023]
Abstract
Femtosecond spectroscopy is an important tool used for tracking rapid photoinduced processes in a variety of materials. To spatially map the processes in a sample would substantially expand the method's capabilities. This is, however, difficult to achieve, due to the necessity of using low-noise detection and maintaining feasible data acquisition time. Here, we demonstrate realization of an imaging pump-probe setup, featuring sub-100 fs temporal resolution, by using a straightforward modification of a standard pump-probe technique, which uses a randomly structured probe beam. The structured beam, made by a diffuser, enabled us to computationally reconstruct the maps of transient absorption dynamics based on the concept of compressed sensing. We demonstrate the setup's functionality in two proof-of-principle experiments, where we achieve spatial resolution of 20 μm. The presented concept provides a feasible route to imaging, by using the pump-probe technique and ultrafast spectroscopy in general.
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