Pixel elements including light emitters of variable heights

A head-mounted display, comprising:

• a light source comprising a plurality of pixel elements configured to emit image light that includes at least two different optical bands of light, the light source further comprising:
• a first sub-pixel mounted on a first set of microbumps at a first height from a substrate and configured to emit light within a first optical band, and
• a second sub-pixel mounted on a second set of microbumps at a second height from the substrate that is different from the first height, and the second sub-pixel is configured to emit light over a second optical band that is different than the first optical band, each of the first sub-pixel and the second sub-pixel comprising a plurality of light emitting elements;
• and
• an optical block configured to receive the image light from the light source, and direct the image light to an eyebox, wherein the first height and the second height are configured to mitigate longitudinal chromatic aberration in the optical block.