GaInAsP/InP Multiple Short Cavity Laser with λ/4-Air Gap/Semiconductor Bragg Reflectors

Abstract
A room temperature operation of multiple cavity (MC) laser consisting of λ/4-air gap (=0.39 µm) and semiconductor reflectors was fabricated using two steps organometallic vapour-phase epitaxy (OMVPE) and two steps wet chemical etching. The threshold current as low as 78 mA (J th = 1.25 kA/cm2) was obtained for a total cavity length 164 µm (Pitch Λ: 20 µm; 8 elements) and stripe width of 40 µm. The effective power reflectivity of this cavity structure was estimated to be higher than 92%.