Illumination apparatus having an array of micro-LEDs and a plurality of catadioptric optical elements configured to output light from the array of micro-LEDs

An illumination apparatus comprising:

• a plurality of LEDs arranged in an LED array, wherein the plurality of LEDs are micro-LEDs or mini-LEDs, each of the plurality of LEDs being arranged to output light having a respective light output distribution;
• and
• a plurality of catadioptric optical elements arranged in a catadioptric optical array, each catadioptric optical element comprising a reflective surface and a transmissive surface facing the reflective surface, wherein:
• for each catadioptric optical element, the reflective surface is arranged to receive light output from one or more of the LEDs through the transmissive surface and to reflect the received light back through the transmissive surface, thereby to provide re-directed light having a respective light output distribution,
• wherein the light output distribution of the re-directed light provided by each catadioptric optical element has a luminous intensity half maximum solid angle that is smaller than the luminous intensity half maximum solid angle of the light output distribution of the light output by each of the plurality of LEDs.