Beam diagnostics and feedback system and method for spectrally beam-combined lasers

A method comprising:

• providing a plurality of fiber lasers that generate a plurality of laser beams, wherein each of the plurality of laser beams is at one of a plurality of substantially monochromatic light wavelengths, the plurality of fiber lasers including a first fiber laser that generates a first laser beam at a first wavelength and a second fiber laser that generates a second laser beam at a second wavelength;
• spectrally combining the plurality of laser beams into a single combined beam;
• setting an adjustable characteristic of the first fiber to generate the first laser beam at a first wavelength;
• setting an adjustable characteristic of the second fiber to generate the second laser beam at a second wavelength;
• detecting that one of the laser beams has become misadjusted relative to the single combined beam, wherein the detecting includes focussing an image of the plurality of light beams onto a plurality of light sensors;
• determining that the first laser beam is the misadjusted one;
• and
• changing the adjustable characteristic of the first fiber laser in order that the first laser beam is improved relative to the single combined beam.

An apparatus comprising:

• a plurality of fiber lasers that generate a plurality of laser beams, wherein each of the plurality of laser beams is at one of a plurality of substantially monochromatic light wavelengths, the plurality of fiber lasers including a first fiber laser that generates a first laser beam at a first wavelength and a second fiber laser that generates a second laser beam at a second wavelength;
• means for spectrally combining the plurality of laser beams into a single combined beam;
• means for setting an adjustable characteristic of the first fiber to generate the first laser beam at a first wavelength;
• means for setting an adjustable characteristic of the second fiber to generate the second laser beam at a second wavelength;
• means for detecting that one of the laser beams has become misadjusted relative to the single combined beam, wherein the means for detecting includes means for focussing an image of the plurality of light beams onto means for sensing light;
• means for determining that the first laser beam is the misadjusted one;
• and
• means for changing the adjustable characteristic of the first fiber laser in order that the first laser beam is improved relative to the single combined beam.