A high-sensitivity femtosecond to microsecond time-resolved infrared vibrational spectrometer

Area of Science:

• Spectroscopy
• Physical Chemistry
• Chemical Physics

Background:

• Bridging the gap between femtosecond and microsecond time scales is crucial for understanding dynamic processes.
• Conventional time-resolved vibrational spectroscopy methods have limitations in temporal resolution or sensitivity.

Purpose of the Study:

• To develop and present a novel apparatus for seamless time-resolved Raman and infrared vibrational spectroscopy.
• To enable high-sensitivity infrared spectroscopy of transient species with broad temporal coverage.

Main Methods:

• An actively Q-switched sub-nanosecond pulsed kilohertz laser synchronized with an ultrafast titanium sapphire regenerative amplifier.
• Utilizing the synchronized laser system to probe transient species with infrared vibrational spectroscopy.
• Achieving synchronization within 0.2 nanoseconds for precise time resolution.

Main Results:

• Demonstration of a seamless bridge between femtosecond and microsecond time-resolved vibrational spectroscopy.
• Acquisition of time-resolved infrared spectra of excited-state relaxation dynamics in metal carbonyl compounds.
• Resolution of transient data from 1 picosecond to over 100 microseconds.

Conclusions:

• The developed apparatus effectively bridges the temporal gap in vibrational spectroscopy.
• The system provides high sensitivity for studying excited-state dynamics of transient species.
• This technology offers a significant advancement over conventional nanosecond Fourier transform infrared (FT-IR) and flash photolysis techniques.