Coherent fiber bundle parallel optical links

An optical transmitter and communication medium for data communications between optical transmitters and optical receivers, comprising:

• an optical transmitter array comprising a plurality of individual transmitters each including a microLED, and microLED collection optics, the microLEDs of the optical transmitter array all attached to a first single substrate, the microLEDs arranged in a regular pattern in a square or hexagonal grid, the microLED collection optics comprising a reflector on the first single substrate for each microLED, so as to reduce an angular cone of optical distribution of the microLED;
• a fiber bundle comprised of a plurality of multimode fibers, each fiber including a core to receive light from a corresponding one of the microLEDs;
• and
• an optical coupling assembly coupling the fiber bundle to the optical transmitter array, the optical coupling assembly being between the optical transmitter array and the fiber bundle.