A 3D micro display, the 3D micro display including: a first single crystal layer including a first plurality of light emitting diodes (LEDs), a second single crystal layer including a second plurality of light emitting diodes (LEDs), where the first single crystal layer includes at least ten individual first LED pixels, where the second single crystal layer includes at least ten individual second LED pixels, where the first plurality of light emitting diodes (LEDs) emits a first light with a first wavelength, where the second plurality of light emitting diodes (LEDs) emits a second light with a second wavelength, where the first wavelength and the second wavelength differ by greater than 10 nm, and where the 3D micro display includes an oxide to oxide bonding structure.