1 research outputs found
Multidimensional Widefield Infrared-Encoded Spontaneous Emission Microscopy: Distinguishing Chromophores by Ultrashort Infrared Pulses
Photoluminescence
(PL) imaging has broad applications in visualizing
biological activities, detecting chemical species, and characterizing
materials. However, the chemical information encoded in the PL images
is often limited by the overlapping emission spectra of chromophores.
Here, we report a PL microscopy based on the nonlinear interactions
between mid-infrared and visible excitations on matters, which we
termed MultiDimensional Widefield Infrared-encoded Spontaneous Emission
(MD-WISE) microscopy. MD-WISE microscopy can distinguish chromophores
that possess nearly identical emission spectra via conditions in a
multidimensional space formed by three independent variables: the
temporal delay between the infrared and the visible pulses (t), the wavelength of visible pulses (λvis), and the frequencies of the infrared pulses (ωIR). This method is enabled by two mechanisms: (1) modulating the optical
absorption cross sections of molecular dyes by exciting specific vibrational
functional groups and (2) reducing the PL quantum yield of semiconductor
nanocrystals, which was achieved through strong field ionization of
excitons. Importantly, MD-WISE microscopy operates under widefield
imaging conditions with a field of view of tens of microns, other
than the confocal configuration adopted by most nonlinear optical
microscopies, which require focusing the optical beams tightly. By
demonstrating the capacity of registering multidimensional information
into PL images, MD-WISE microscopy has the potential of expanding
the number of species and processes that can be simultaneously tracked
in high-speed widefield imaging applications