Internal Optical Loss in Semiconductor Lasers

Abstract

Internal optical loss in high-power semiconductor lasers based on quantum-well separate-confinement heterostructures was studied. Calculations show that the major portion of the internal optical loss occurs in the active region and emitters. Making the laser waveguide thicker and the cavity longer reduces the internal optical loss. Two possible approaches to the design of laser heterostructures are considered, and optimal solutions are suggested. The difference in the internal optical loss between lasers on InP and those on GaAs substrates is attributed to the larger cross section of photon absorption by holes in InP. Good agreement between the calculated and experimental values of the internal optical loss in lasers on InP and GaAs substrates is obtained. © 2004 MAIK "Nauka/Interperiodica".