Fundamental Transverse Mode Selection (TMS#0) of Broad Area Semiconductor Lasers with Integrated Twice-Retracted 4f Set-Up and Film-Waveguide Lens

Figure 4

Experimental results, that is, near- (a) and far-field (b) intensity distributions, for a BAL without spatial filter or waveguide lens for com parison. The laser has exactly the same layer sequence as that with the results in Figure 5, since both lasers have been made from the same wafer. The measurements are performed at 91 K device temperature in continuous wave operation. As expected there is no evidence of fundamental transverse mode selection (TMS#0).

(a)

(b)