Wavefront control of subcycle vortex pulses via carrier-envelope-phase tailoring

Area of Science:

• Quantum Optics
• Ultrafast Laser Physics
• Wavefront Engineering

Background:

• The carrier-envelope phase (CEP) is critical for characterizing ultrashort laser pulses, especially in the subcycle regime.
• Spatiotemporal coupling in structured optical pulses, like optical vortices (OV), links CEP to spatial characteristics.
• Direct observation of CEP's spatial effects in subcycle OV pulses has been lacking.

Purpose of the Study:

• To measure and control the spatial wavefront of subcycle OV pulses by manipulating the CEP.
• To demonstrate the spatial impact of CEP control in structured ultrashort laser pulses.

Main Methods:

• Generation of subcycle OV pulses using an optical parametric amplifier and a Sagnac interferometer.
• Development of a novel π-2π interferometer for wavefront analysis.
• Utilizing the second harmonic of a Gaussian pulse as a reference parabolic wavefront.

Main Results:

• Successfully generated 4.7 fs OV pulses at 1.54 µm.
• Observed the rotation of spiral interference fringes by adjusting the CEP.
• Demonstrated direct spatial wavefront control via CEP manipulation in subcycle OV pulses.

Conclusions:

• CEP control directly influences the spatial wavefront of subcycle OV pulses.
• The developed interferometer enables precise measurement of CEP-induced spatial effects.
• This work opens new avenues for spatiotemporal control in ultrafast optics.