Non-diffracting linear-shift point-spread function by focus-multiplexed computer-generated hologram.

Area of Science:

• Optics and Photonics
• Computational Imaging
• Metrology

Background:

• Airy beams enable non-diffracting self-bending point-spread functions (PSFs) for 3D imaging.
• Parabolic spot trajectories in Airy beams limit range and resolution in rangefinding.
• Existing methods struggle with precise depth-dependent trajectory control.

Purpose of the Study:

• To propose a novel pupil-phase-modulation method for realizing a non-diffracting linear-shift PSF.
• To overcome the limitations of parabolic trajectories in existing non-diffracting beams.
• To improve range and resolution in rangefinding and 3D imaging applications.

Main Methods:

• Utilized a focus-multiplexed computer-generated hologram for pupil-phase modulation.
• Calculated the hologram by multiplexing multiple lens-function holograms with 2D focal sweeping.
• Verified the proposed method through numerical simulations and optical experiments.

Main Results:

• Successfully realized a non-diffracting linear-shift PSF.
• Demonstrated a straightened depth-dependent trajectory of the non-diffracting spot.
• Achieved significant improvements in range and resolution for rangefinding.

Conclusions:

• The proposed pupil-phase-modulation method effectively linearizes the PSF trajectory.
• This technique enhances performance in applications requiring precise depth measurements.
• Potential applications include laser-based microscopy and time-of-flight rangefinding.