Thermal lensing in high-power ridge-waveguide lasers

Hans Wenzel, M. Dallmer, G. Erbert
2007 2007 International Conference on Numerical Simulation of Optoelectronic Devices  
Outline • motivation and laser structure • experimental results • theoretical model • simulation results • conclusions Motivation • fundamental-spatial mode diode lasers with an output power in the 1-W range of interest for a variety of applications • requires narrow lateral waveguide defined by small effective index step to cut-off higher order modes • at higher output power appearance of instabilities like kinks in light-current characteristics beam steering appearance of higher order modes •
more » ... possible reasons: carrier-induced index suppression thermal lensing spatial hole burning Schematic cross-sectional view of RW devices trench p-contact metal insulator active layer ridge B W residual layer thickness x • finite trench width =⇒ radiation leaks into the outer high-index regions • radiation loss rises with mode number =⇒ stabilization of 0th order mode • anti-index guiding =⇒ sensitive to thermal lensing effect Experimental light-current characteristics • cavity length L = 3.9 mm • ridge width W = 2.8 µm • emission wavelength around λ = 1064 nm • output power P > 1.3 W at I = 2 A • only small difference in the characteristics for trench widths B = 20 µm and B = 5 µm • strong increase of threshold current and decrease of slope efficiency slightly above threshold for B = 2.5 µm 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 0 . 0 0 . 5
doi:10.1109/nusod.2007.4349000 fatcat:szd7h4dglzdmvcihlumb7miia4