Title :
940-nm Broad Area Diode Lasers Optimized for High Pulse-Power Fiber Coupled Applications
Author :
Platz, Rene ; Eppich, B. ; Crump, P. ; Pittroff, Wolfgang ; Knigge, S. ; Maassdorf, Andre ; Erbert, Gotz
Author_Institution :
Leibniz-Inst. fur Hochstfrequenztechnik, Ferdinand-Braun-Inst., Berlin, Germany
Abstract :
Diode lasers with 400- μm stripe widths measured in pulsed-current mode are shown to reach peak (saturation) powers of 60 W for 1-ms pulses (60 mJ) and 189 W for 300-ns pulses ( ~ 55 μJ). Use of laterally structured contact and etched index guides at the stripe edges enables these devices to sustain stable lateral near- and far-field profiles to the highest bias, with a lateral beam parameter product of . Optical calculations are presented for an example system where arrays of these single emitters are incoherently coupled into a fiber with 1-mm core and numerical aperture of 0.22, extrapolating 5 kW in fiber for 1 ms (5 J) and 18 kW in fiber for 300-ns pulses ( ~ 5 mJ). Such sources would be well suited for pumping Yb:YAG crystals for applications needing high beam quality, or as direct sources.
Keywords :
laser beams; laser modes; optical fibre couplers; optical pumping; semiconductor laser arrays; ytterbium; YAG:Yb; Yb:YAG crystals; beam quality; broad area diode lasers; direct sources; energy 60 mJ; etched index guides; extrapolation; far-field profiles; high pulse-power fiber coupled applications; lateral beam parameter product; laterally structured contact index guides; numerical aperture; optical calculation; power 18 kW; power 5 kW; pulsed-current mode; single emitter arrays; size 400 mum; stable lateral near-field profiles; stripe edges; time 1 ms; time 300 ns; wavelength 940 nm; Current measurement; Diode lasers; Laser beams; Optical fiber devices; Optical fibers; Optical pulses; Performance evaluation; Diode laser; fiber coupling; high power; lateral structure; pulsed source;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2014.2301881