Shaped fibers for efficient beam combination

An optical assembly, comprising:

• multiple laser modules configured to emit respective beams;
• a feeding fiber;
• and
• a fiber optic combiner coupled between the multiple laser modules and the feeding fiber,
• wherein the fiber optic combiner comprises multiple optical fibers bundled within an enclosing tube,
• wherein the multiple optical fibers bundled within the enclosing tube each include a core and a non-circular cladding surrounding the core,
• wherein the non-circular cladding has a shape quantified by one or more parameters,
• wherein the shape of the non-circular cladding is triangular with three flattened edges, and
• wherein the one or more parameters include a flat depth parameter having a value equal to a difference between a radius of an optical fiber of the multiple optical fibers and a distance from a center of the optical fiber to at least one of the three flattened edges.

A method, comprising:

• receiving multiple preforms that each have a core and a circular cladding surrounding the core;
• forming multiple optical fibers having non-circular shapes by removing material from the circular cladding surrounding the core of each of the multiple preforms;
• and
• bundling the multiple optical fibers within an enclosing tube having a geometric shape,
• wherein, after removing the material from the circular cladding, the multiple optical fibers have non-circular cladding having a shape quantified by one or more parameters,
• wherein the shape of the non-circular cladding is nearly circular with at least one flattened edge, and
• wherein the one or more parameters include a flat depth parameter having a value equal to a difference between a radius of an optical fiber of the multiple optical fibers and a distance from a center of the optical fiber to the at least one flattened edge.