Optical cross-coupling mitigation systems for wavelength beam combining laser systems

A laser system comprising:

• an array of beam emitters each emitting a beam having a different wavelength;
• focusing optics for focusing the beams toward a dispersive element;
• a dispersive element for receiving and dispersing the focused beams, thereby forming a multi-wavelength beam;
• a cross-coupling mitigation system for receiving and transmitting the multi-wavelength beam while reducing cross-coupling thereof;
• disposed optically downstream of the cross-coupling mitigation system, an optical fiber for receiving the multi-wavelength beam;
• and
• disposed within the optical fiber, a fiber Bragg grating for receiving the multi-wavelength beam, reflecting a first portion thereof back toward the cross-coupling mitigation system, and transmitting a second portion thereof as an output beam composed of multiple wavelengths.

A method of coupling a laser beam to an optical fiber having (i) a core and (ii) a cladding surrounding the core, the method comprising:

• emitting a plurality of beams each having a different wavelength from a plurality of beam emitters;
• wavelength-dispersing the plurality of beams to form a multi-wavelength beam;
• reflecting a first portion of the multi-wavelength beam back to the plurality of beam emitters with the core of an optical fiber, the first portion of the multi-wavelength beam stabilizing each of the beams to its wavelength;
• and
• transmitting a second portion of the multi-wavelength beam through the core of the optical fiber as an output beam composed of multiple wavelengths.