Dynamic ultraviolet harmonic beam pattern control by programmable spatial wavefront modulation of near-infrared...

Area of Science:

• Optics and Photonics
• Laser Physics
• Ultrafast Science

Background:

• Ultraviolet (UV) light is crucial for semiconductor lithography, spectroscopy, and imaging due to its high resolution and photon energy.
• Existing methods for UV beam control face challenges due to material absorption and stringent precision requirements for optics.
• Dynamic manipulation of UV laser beams is limited, hindering broader applications.

Purpose of the Study:

• To demonstrate a novel method for dynamic control of ultraviolet (UV) harmonic beam patterns.
• To enable precise wavefront manipulation of UV laser beams using a femtosecond pulse laser.
• To facilitate advanced applications such as high-precision laser patterning and polarization-sensitive encryption.

Main Methods:

• Manipulation of the near-infrared (NIR) wavefront of a fundamental femtosecond pulse laser.
• Utilizing the preserved temporal and spatial coherences in optical harmonic generation.
• Employing a non-collinear harmonic generation configuration to separate UV beams from the fundamental IR beam.

Main Results:

• Demonstrated dynamic control over the spatial beam distribution of UV harmonic beams (266 nm and 400 nm).
• Achieved fast polarization-sensitive UV beam switching at 6.7 frames/s with depth-resolving capability.
• Validated the potential for expansion to higher-order harmonics in vacuum ultraviolet (VUV) and extreme ultraviolet (EUV) regimes.

Conclusions:

• The developed technique offers facile and dynamic control over UV laser beam wavefronts.
• This approach overcomes limitations of conventional UV optics, enabling arbitrary wavefront control.
• The method paves the way for advanced applications including high-precision laser patterning, polarization-sensitive encryption, and 3D holograms.