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

Figure 2

Current concept: sketches and SEM micrographs (top-views) of a TMS#0-BAL with compact linear f long laser resonator (4f set-up “retrac ted twice”) and spatial filter to support the fundamental transverse mode (#0). The central filter segment has a width of = 30 μm.