Field-Evolving Cavity Aperture Extension for Compact Lightfield Displays

The patent implements aperture extension by nesting multiple virtual aperture positions within a single physical cavity structure. Light is reflected multiple times between entrance and exit facets, creating the effect of multiple aperture planes without requiring multiple physical apertures. This nesting approach allows a compact cavity to provide extended aperture functionality that would otherwise require a much larger physical structure.

The patent introduces a field-evolving cavity as an intermediary optical element between the light source and the final image plane. This cavity mediates the light propagation by controlling multiple reflections and path lengths, enabling aperture extension and depth modulation without directly modifying the light source or detector. The cavity acts as a programmable optical processor that transforms limited physical aperture into extended functional aperture.

The patent employs dynamic control of the optical cavity properties through programmable modulation of reflection coefficients at the entrance and exit facets. By dynamically adjusting the reflectivity of these facets, the system can control the number of round trips light makes within the cavity, thereby controlling both the optical path length and minimizing light leakage. This dynamic control allows optimization of depth range while suppressing harmful light leakage.

The patent changes the optical parameters of the cavity facets, specifically the reflection coefficient, to control light circulation. By modulating the reflectivity parameter of the half-mirrors, the system can extend the optical path length for depth modulation while maintaining control over light loss. This parameter control enables the system to achieve extended depth range without uncontrolled light leakage.

The patent replaces mechanical aperture extension mechanisms with polarization-based optical control. Instead of physically moving or expanding aperture structures, the system uses polarization-dependent reflection to create virtual aperture extension. This substitution of mechanical systems with optical field control reduces the stringent mechanical manufacturing precision requirements while achieving the same functional effect.

The patent exploits changes in polarization state as a controllable parameter to achieve aperture extension. By using polarization-dependent half-reflective surfaces, the system can selectively reflect or transmit light based on its polarization state, creating extended aperture effects without requiring precise mechanical alignment. This parameter-based control (polarization state) is more tolerant to manufacturing variations than mechanical positioning.