Fourier Transform Coherent Anti-Stokes Raman Scattering Spectroscopy: A Comprehensive Review.

Fourier transform coherent anti-Stokes Raman scattering (FT-CARS) spectroscopy is a powerful spectroscopic method that combines the principles of Fourier transform spectroscopy with coherent anti-Stokes Raman scattering (CARS). This method stands out in spectroscopy for its ability to rapidly acquire coherent Raman spectra, achieving an impressive rate of over 10 000 spectra per second. The method involves scanning the optical delay between two femtosecond pulses; the initial pulse induces a vibrational coherence in the sample, while the subsequent pulse probes this coherence over increasing delays.

Fluorescence-Encoded Time-Domain Coherent Raman Spectroscopy in the Visible Range.

Fluorescence-encoded vibrational spectroscopy has attracted increasing attention by virtue of its high sensitivity and high chemical specificity. We recently demonstrated fluorescence-encoded time-domain coherent Raman spectroscopy (FLETCHERS), which enables low-frequency vibrational spectroscopy of low-concentration fluorophores using near-infrared (800-900 nm) light excitation. However, the feasibility of this study was constrained by the scarcity of excitable molecules in the near-infrared range.

Singlet fission as a polarized spin generator for dynamic nuclear polarization.

Singlet fission (SF), converting a singlet excited state into a spin-correlated triplet-pair state, is an effective way to generate a spin quintet state in organic materials. Although its application to photovoltaics as an exciton multiplier has been extensively studied, the use of its unique spin degree of freedom has been largely unexplored. Here, we demonstrate that the spin polarization of the quintet multiexcitons generated by SF improves the sensitivity of magnetic resonance of water molecules through dynamic nuclear polarization (DNP).