Sub-attosecond-precision optical-waveform stability measurements using electro-optic sampling.

Area of Science:

• Quantum Optics
• Precision Metrology
• Ultrafast Lasers

Background:

• Controlled optical waveforms are crucial for precision metrology in both time and frequency domains.
• Existing methods for measuring optical waveform dynamics face limitations in sensitivity and bandwidth.

Purpose of the Study:

• To generate and characterize mid-infrared (mid-IR) laser pulses with controlled optical waveforms.
• To validate electro-optic sampling (EOS) as a sensitive, broadband technique for measuring waveform jitter.
• To demonstrate the stability of mid-IR waveforms generated via intra-pulse difference-frequency generation (IPDFG).

Main Methods:

• Generation of mid-IR waves using intra-pulse difference-frequency generation (IPDFG) driven by 16-fs near-infrared pulses.
• Characterization of sub-cycle waveform jitter using electro-optic sampling (EOS).
• Analysis of wavelength-dependent jitter by chirping the mid-IR pulses.

Main Results:

• Demonstrated sub-attosecond temporal jitter at individual zero-crossings of the optical waveform.
• Achieved sub-0.1% relative amplitude fluctuations in the 10 kHz–0.625 MHz band.
• Uncovered wavelength-dependent attosecond-scale waveform jitter for chirped mid-IR pulses.

Conclusions:

• EOS is a highly sensitive, broadband measurement technique for optical waveform jitter dynamics.
• IPDFG and EOS yield mid-IR waveforms with outstanding stability, benefiting precision measurements.
• The findings pave the way for EOS-based active waveform stabilization and multi-oscillator synchronization.