High spatiotemporal resolution in multifocal processing with femtosecond laser pulses

Area of Science:

• Optics and Photonics
• Ultrafast Laser Technology
• Material Processing

Background:

• Femtosecond pulses are crucial for high-resolution material processing.
• Dispersion and spatial walk-off limit the effectiveness of femtosecond pulses.
• Existing methods struggle with simultaneous spatial and temporal dispersion compensation.

Purpose of the Study:

• To achieve spatial and temporal dispersion compensation for femtosecond pulses.
• To create a multifocal light structure with diffraction-limited spots.
• To enable parallel material processing with high spatiotemporal resolution.

Main Methods:

• Utilizing a hybrid diffractive-refractive lens triplet.
• Employing a low-frequency diffraction grating.
• Implementing spatial chromatic compensation.

Main Results:

• Achieved nearly diffraction-limited multifocal light spots for 20 fs pulses.
• Significantly reduced lateral walk-off of spectral components.
• Improved bandwidth at dispersion-compensated diffraction orders.
• Demonstrated that output pulse width is limited by a small group-delay dispersion term.

Conclusions:

• The proposed hybrid lens system effectively compensates for spatial and temporal dispersion.
• High spatiotemporal resolution enables efficient parallel multifocal processing.
• This technology advances the capabilities of ultrafast laser material applications.