Versatile Femtosecond Laser Synchronization for Multiple-Timescale Transient Infrared Spectroscopy

Area of Science:

• Physical Chemistry
• Spectroscopy
• Photochemistry

Background:

• Femtosecond laser systems are crucial for studying ultrafast chemical and biological processes.
• Synchronizing different laser systems is challenging but essential for probing extended timescales.
• Current methods often require mechanical delay stages, limiting experimental flexibility.

Purpose of the Study:

• To present versatile electronic synchronization methods for diverse femtosecond laser systems.
• To enable rapid probing of timescales from picoseconds to seconds in transient absorption experiments.
• To overcome limitations of mechanical delay stages in ultrafast spectroscopy.

Main Methods:

• Arbitrary-detuning asynchronous optical sampling (ADASOPS).
• Active locking of femtosecond laser oscillators (not necessarily to the same round-trip frequency).
• Utilizing a single freely programmable electronics hardware for synchronization.

Main Results:

• Successful synchronization of disparate laser systems (e.g., Ti:Sa amplifier and 100 kHz Yb-laser).
• Achieved time-resolution (jitter) in the range of 1-3 picoseconds.
• Demonstrated transient IR measurements of excited state dynamics and a full protein reaction cycle.

Conclusions:

• The presented electronic synchronization methods offer a versatile and powerful tool for ultrafast spectroscopy.
• These techniques open new avenues for investigating long-lasting processes in photochemistry and photoactive proteins.
• The methods provide a flexible alternative to mechanical delay stages, enhancing experimental efficiency.