Transverse Mode Controlled Wide-Single-Stripe Lasers By Loading Modal Filters

A theory of broad-area semiconductor lasers with modal reflectors

“…Similar observations follow from the threshold analysis which revealed that for the 50 µm stripe J (0) th − J (4) th = −102 A cm −2 , whereas for the 80 µm stripe J (0) th − J (1) th = −12 A cm −2 . These results confirm the relevant plots reported by Ikeda et al [9]. For completeness we provide in figure 4 the far-field pattern of the fundamental mode, calculated for the 50 µm stripe at J = 610 A cm −2 .…”

“…The other approach involves broad-area (BA) lasers (stripe width of 50 µm or more) with cavities modified to favour the oscillation of their fundamental lateral modes. Among the many BA laser configurations such as those with unstable resonators [2], tilted mirrors [3], external cavities [4] or periodic gain sections [4], BA lasers with modal reflectors have appeared as a promising solution [6][7][8][9][10][11][12].…”

“…The concept of the modal reflector formed by patterning the reflectivity of the laser facet was introduced by Suematsu and Yamada, who analysed theoretically the mode dependence of diffraction losses resulting from the finite width of the rectangular resonator mirror [6]. To date several attempts have been made to employ a narrow reflecting stripe on the emitting facet, as an effective tool for lateral mode control [7][8][9][10][11]. However, the experimental results presented in [11] revealed that the lasing mode in such a structure can be an interferometer mode determined by the mirror configuration, rather than the desired lateral mode of the laser's guiding stripe.…”