Polarization-selective computer-generated holograms: design, fabrication, and applications

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Traditional optical elements lack polarization selectivity.
• Controlling light polarization independently for different orientations is crucial for advanced optical systems.

Purpose of the Study:

• To design and fabricate polarization-selective computer-generated holograms (CGHs).
• To achieve independent phase control for horizontal and vertical light polarizations.
• To explore potential applications of this holographic technology.

Main Methods:

• Constructing CGHs from two surface-relief-etched birefringent substrates.
• Developing a design methodology for arbitrary substrate and gap materials.
• Utilizing standard microelectronics fabrication technology.
• Applying a single-layer SiO(2) thin-film antireflection coating.

Main Results:

• Demonstrated a diffraction efficiency of 60% with a polarization contrast ratio exceeding 100:1.
• Successfully fabricated multilevel phase holograms using lithium niobate substrates.
• Showcased experimental applications including a dual focal-length lens and a 2x2 polarization switch.
• Verified minimal impact of antireflection coatings on hologram performance.

Conclusions:

• Polarization-selective CGHs offer precise control over light polarization.
• The fabrication method is compatible with standard microelectronics processes.
• This technology enables novel optical devices like polarization-controlled lenses and switches.