Mode multiplexing optical coupling device

An optical fiber device, comprising:

• a tapered fiber bundle having a plurality of input fibers, adiabatically tapered, and heavily-fused into an induced compact shape with minimally deformed cores and no interstitial space between the input fibers at a cleaved end;
• and
• an output element coupled to the cleaved end.

A method of manufacturing an optical fiber device, comprising:

• i) positioning a plurality of optical fibers in a predetermined configuration for forming an optimized encircling radius;
• (ii) bundling the positioned plurality of optical fibers while controlling the tension applied on individual fibers to result in a fiber bundle with minimized overall diameter;
• (iii) heating and pulling the fiber bundle to heavily fuse the fiber bundle in an adiabatically tapered region into an induced shape with no interstitial space between fibers.

A star coupler, comprising:

• a tapered fiber bundle formed in the midsection of a plurality of fibers, adiabatically tapered, and heavily-fused into an induced compact shape with minimally deformed cores and no interstitial space between the fibers, such that the plurality of fibers form input and output leads on each side of the fused bundle.

The star coupler of claim 28, wherein at least one of the input leads is terminated to reduce back reflections.