Coherent multi-dimensional widefield microscopy

TL;DR

This paper introduces a novel widefield microscopy technique combining multidimensional coherent spectroscopy with optical imaging, achieving femtosecond temporal and micrometer spatial resolution to study quantum coherence in 2D materials.

Contribution

The development of a 2DES microscope that captures spatially resolved electronic spectra without scanning, enabling new insights into ultrafast dynamics in heterogeneous systems.

Findings

Revealed spatial variations in excitonic dynamics in bilayer WSe2.

Validated 2DESM as a tool for probing quantum coherence and many-body interactions.

Demonstrated simultaneous spectral and spatial imaging at femtosecond and micrometer scales.

Abstract

We present a widefield two-dimensional electronic spectroscopy microscope (2DESM) that integrates multidimensional coherent spectroscopy with optical imaging, enabling femtosecond temporal and micrometer spatial resolution. The broadband coverage (1.4-1.8 eV) allows the direct acquisition of spatially resolved two-dimensional electronic spectroscopy (2DES) maps of relevant near infrared excitations without the need for spatial scanning. By capturing both spectral and spatial domains simultaneously, 2DESM overcomes limitations of pump-probe microscopy and scanning 2DES, providing access to decoherence dynamics, inhomogeneous broadening, and coherent coupling in heterogeneous systems. As a proof-of-concept we performed 2DESM measurements on bilayer WSe2 encapsulated in hBN, revealing distinct spatial variations in excitonic dynamics. These results validate the ability of 2DESM to link local environments with ultrafast coherent processes and establish 2DESM as a versatile platform for probing quantum coherence, many-body interactions, and non-local energy transfer in two-dimensional materials, heterostructures, and micrometer-scale optoelectronic devices.