Device for performing semiconductor laser external cavity feedback spectral beam combining by using multiple gratings

The present invention discloses a device for performing semiconductor laser external cavity feedback spectral beam combining by using multiple gratings. The device comprises a laser array, a fast axis collimating lens, a beam combining lens, a first-stage grating, a beam combining component, a second-stage grating and a feedback element; the laser array comprises M laser linear arrays, wherein each laser linear array comprises a plurality of laser units; laser beams emitted by the laser units on each laser line array are collimated by the fast axis collimating lens, and the collimated laser beams are parallelly emitted to the beam combining lens; the beam combining lens performs beam combining on the laser beams and sends a combined laser beam to the first-stage grating, so that one laser beam can be obtained; M laser beams are emitted from the first-stage grating; the beam combining component performs beam combining on the M laser beams and emits one combined laser beam to the second-stage grating; and the feedback element performs wavelength locking on the combined laser beam, so that high-power and high-quality semiconductor direct output laser can be obtained. With the device of the invention adopted, the spectral beam combining of the plurality of laser linear arrays can be realized simultaneously, and the quality of the obtained laser beam is equivalent to that of the laser beam of a single laser unit, and output power is far beyond a semiconductor laser light source of a single laser linear array.