Leaky-mode waveguide modulators with high deflection angle for use in holographic video displays

Area of Science:

• Optics and Photonics
• Display Technology
• Materials Science

Background:

• Holographic video displays typically require complex optics to magnify viewing angles and overcome display limitations.
• Existing systems often necessitate demagnification and derotation, adding complexity and bulk.

Purpose of the Study:

• To report a novel leaky mode waveguide spatial light modulator (SLM) capable of high angular diffraction.
• To demonstrate that this SLM can eliminate the need for external optics in scanned aperture holographic displays.

Main Methods:

• Experimental investigation of annealed, proton-exchanged waveguides to identify optimal depths for maximized diffraction angles.
• Measurement of diffraction sweeps using a leaky mode waveguide SLM at 632.8 nm wavelength.

Main Results:

• Achieved diffraction sweeps exceeding 19.5°, surpassing the 15° threshold required for direct-view holographic displays.
• The achieved diffraction angle corresponds to a relatively narrow input bandwidth of 70 MHz.
• Proposed device geometries that could potentially achieve over 20° total angular sweep for red, green, and blue light.

Conclusions:

• The developed leaky mode waveguide SLM offers a significant advancement in holographic display technology by enabling wider viewing angles.
• This technology has the potential to simplify holographic video display systems by removing the need for auxiliary optical components.
• Future work could focus on optimizing device designs for full-color holographic video applications.