Apparatus and method for realizing spectrum beam combination through external cavity feedback

The invention discloses an apparatus and a method for realizing spectrum beam combination through external cavity feedback. The apparatus for realizing the spectrum beam combination through the external cavity feedback comprises at least two laser arrays, at least two fast-axis lenses, at least two pairs of reflecting mirror groups, a conversion lens, an optical grating, and an external cavity mirror, wherein one laser array corresponds to one fast-axis lens and one reflecting mirror group; two adjacent laser arrays are arranged according to a distance period L; a light beam of each laser array passes through the corresponding fast-axis lens and then is turned for 180 degrees through one pair of the reflecting mirror groups; the distance between two adjacent reflecting mirror groups is L/2; and the light path distances from the laser arrays to the conversion lens are the same. Therefore, by adoption of the apparatus and the method, the spectrum beam combination of multiple conduction-cooled packaged laser arrays can be realized only by one conversion lens and one optical grating; light beams which pass through the conversion lens are focused on the optical grating; and the light beams are subjected to the spectrum beam combination through the external cavity mirror feedback.