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

<div>Experimental results for a TMS#0-BAL with spatial filter to support the fundamental transverse mode (#0) and with film-waveguide lens. The intensity profiles are taken on the filter side of the resonator. The laser has exactly the same layer sequence as that from Figure <a href="../fig4/">4</a>, since both lasers have been made from the same wafer. Again (a) gives the near-field, (b) the far-field intensity distribution. The measurements are performed at 91 K device temperature in continuous wave operation. Obviously the fundamental transverse mode is strongly supported. But filamentation is not suppressed. Gaussian fits are introduced into the diagrams as red lines.</div>

Advances in OptoElectronics

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Figure 5

Figure 5: Fundamental Transverse Mode Selection (TMS#0) of Broad Area Semiconductor Lasers with Integrated Twice-Retracted 4<i>f</i> Set-Up and Film-Waveguide Lens 

Figure 5 | Fundamental Transverse Mode Selection (TMS#0) of Broad Area Semiconductor Lasers with Integrated Twice-Retracted 4f Set-Up and Film-Waveguide Lens 