Generation of deep ultraviolet sub-2-fs pulses

Area of Science:

• Ultrafast laser science
• Nonlinear optics
• Quantum optics

Background:

• Generating ultrashort pulses in the deep ultraviolet (DUV) spectrum is crucial for various scientific applications.
• Existing methods often face limitations in pulse duration and spectral range.
• Few-cycle pulse generation requires precise control over nonlinear optical processes.

Purpose of the Study:

• To demonstrate the generation of few-cycle DUV pulses via frequency upconversion.
• To achieve record-short pulse durations in the DUV spectral region.
• To explore the potential of laser-fabricated gas cells for ultrafast pulse generation.

Main Methods:

• Frequency upconversion of 5-femtosecond (fs) near-infrared (NIR) pulses in argon.
• Utilizing a laser-fabricated gas cell for efficient nonlinear interaction.
• Employing dispersion-free second-order cross-correlation measurements for pulse duration characterization.

Main Results:

• Successfully generated few-cycle DUV pulses with a measured spectrum spanning 210–340 nm.
• Achieved a transform-limited pulse duration of 1.45 fs.
• Experimentally determined a pulse duration of 1.9 fs, setting a new record for the DUV range.

Conclusions:

• The developed method enables efficient generation of record-short DUV pulses.
• Laser-fabricated gas cells are effective tools for ultrafast nonlinear optics.
• This breakthrough opens new avenues for attosecond science and spectroscopy in the DUV region.