Low-loss Bragg-reflector lateral-transverse-mode confinement in AlGaInP red laser

A low-loss Bragg-reflector-waveguide (BRW) structure is proposed for AlGaInP red lasers. This BRW laser uses (AlGaInP/GaAs)/sub n/ Bragg-reflector (BR) block layers in place of conventional GaAs block layers. Propagating-mode calculations reveal that an aluminum content (x) lower than 0.2 for (Al/sub x/Ga/sub 1-x/)/sub 0.5/In/sub 0.5/P in the BR block layers is sufficient for reducing mode loss together with confining the lateral transverse mode. Mode loss in the (AlGaInP/GaAs)/sub n/ BR region is reduced resonantly to one-third that of a conventional GaAs block region. This reduction originates from a combination of Bragg reflection and the low absorption loss in the AlGaInP crystal. The refractive-index step, formed at the edge of a ridge stripe by the BR block layers, is around 1/spl times/10/sup -2/.<
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