Methods and systems for programming momentum and increasing light efficiency in deeper roundtrips of folded optics and cavities via time-space harmonics and moiré effects

A display system comprising

• a display panel to emit light, and
• wavefront modulating elements, including
• an isotropic retarder, and
• a polarizer disposed after the isotropic retarder, wherein the isotropic retarder and the polarizer do not vary macroscopically transverse to an optic axis, such that an intensity of light from the display panel is modulated to selectively adjust a property of a virtual image.

A display system, comprising

• a light source, and
• an optical subsystem coupled to the display panel, wherein elements comprising the optical subsystem do not vary macroscopically transverse to an optic axis, such that the optical subsystem modulates a wavefront of light from the display panel to produce an image by partial interference of multiple or cascaded reflections,
• wherein the optical subsystem forms a cavity, and the light is folded along a line perpendicular to a line of sight of a user and is coupled out to the user with a trigger signal in a display after at least one round trip in the cavity,
• wherein the trigger signal is an optical signal at a frequency outside the visible spectrum.