Patent ID: 8537865

Claim:
Fiber laser apparatus comprising: a gain-fiber; a band-pass filter including at least one filter element; a partially reflective and partially transmissive feedback mirror; a focusing lens; a plurality of diode-laser bars each thereof including a plurality of diode-laser emitters each emitter for emitting a beam of radiation having a lasing wavelength, the diode-laser bars and emitters therein characterized as having a slow-axis in the length of the diode-laser bars, a fast-axis in the height direction of the diode-laser bars and a propagation axis perpendicular to the fast-axis and the slow-axis; each diode-laser bar having a first collimating lens associated therewith for collimating the beams of radiation from the emitters in the fast-axis, and plurality of second collimating lenses associated therewith for collimating the fast-axis collimated beams in the slow-axis thereby producing a set of fast- and slow-axis collimated beams propagating from each of the diode-laser bars; wherein the fast- and slow-axis collimated beam-sets are transmitted through the band-pass filter in a forward direction on beam-paths parallel to each other in the fast-axis to the feedback mirror, the feedback mirror being arranged to reflect a first portion of the radiation in each of the beams-sets back through the band-pass filter in a reverse direction along the beam paths to the diode-laser bars from which the beam-sets were emitted for locking the lasing wavelength at a value determined by the band-pass filter; and wherein a second portion of the radiation in the beam-sets is transmitted through the feedback mirror to the focusing lens, and focused by the focusing lens into one end of the gain-fiber for optically pumping the gain-fiber.