The vortex beam (Laguerre–Gaussian, LG10 mode) is employed to alleviate crystal damage in multiple-plate continuum generation. We successfully compressed 190-fs, 1030-nm pulses to 42 fs with 590 μJ input pulse energy, which is 5.5 times higher than that obtained by a Gaussian beam setup of the same footprint. High throughput (86%) and high intensity-weighted beam homogeneity (>98%) have also been achieved. This experiment confirms the great potential of beam shaping in energy up-scaling of nonlinear pulse compression.

The exploration of deactivation mechanisms for near-infrared(NIR)-emissive organic molecules has been a key issue in chemistry, materials science and molecular biology. In this study, based on transient absorption spectroscopy and transient grating photoluminescence spectroscopy, we demonstrate that the aggregated Pt II complex 4H (efficient NIR emitter) exhibits collective out-of-plane motions with a frequency of 32 cm À 1 (0.96 THz) in the excited states. Importantly, similar THz characteristics were also observed in analogous Pt II complexes with prominent NIR emission efficiency. The conservation of THz motions enables excited-state deactivation to proceed along low-frequency vibrational coordinates, contributing to the suppression of nonradiative decay and remarkable NIR emission. These novel results highlight the significance of excited-state vibrations in nonradiative processes, which serve as a benchmark for improving device performance.

The control of excited-state vibrational and electronic energy flows in molecular solids has a considerable impact on the performance of optoelectronic devices. In this study, we applied a novel ultrafast pump-probe system with 3.2 fs resolution to demonstrate that the aggregated Pt(II) complex 4H, an efficient near-infrared emitter, exhibits prominent single-mode vibrational coherence (VC) with a frequency of 32 cm−1 (~ 0.96 THz) in the excited state. This single-mode VC is associated with the collective out-of-plane motions induced by intermolecular metal-metal-to-ligand charge transfer transitions, which occur through ultrafast intersystem crossings with lifetimes of 150 fs. Similar single-mode VC characteristics were observed in analogues of 4H and other Pt(II) complexes with intense NIR emission. The conservation of single-mode VC enables excited-state deactivation to proceed along low-frequency coordinates, which contributes to the suppression of nonradiative decay rates and causes highly intense near-infrared emission in aggregated Pt(II) complexes. These novel results highlight the importance of VC in understanding nonradiative processes, elucidating the foundations of VC in molecular solid, which serve as a benchmark for evolving the device performance.

A vortex beam is employed in multiple-plate compression to overcome the crystal damage threshold. 190-fs, 1030-nm pulses are compressed to 42 fs with a pulse energy 5.5 times higher than the Gaussian beam counterpart.

The exploration of deactivation mechanisms for near-infrared(NIR)-emissive organic molecules has been a key issue in chemistry, materials science and molecular biology. In this study, based on transient absorption spectroscopy and transient grating photoluminescence spectroscopy, we demonstrate that the aggregated Pt II complex 4H (efficient NIR emitter) exhibits collective out-of-plane motions with a frequency of 32 cm À 1 (0.96 THz) in the excited states. Importantly, similar THz characteristics were also observed in analogous Pt II complexes with prominent NIR emission efficiency. The conservation of THz motions enables excited-state deactivation to proceed along low-frequency vibrational coordinates, contributing to the suppression of nonradiative decay and remarkable NIR emission. These novel results highlight the significance of excited-state vibrations in nonradiative processes, which serve as a benchmark for improving device performance.