High-performance, strain compensated InGaAs-GaAsP-GaAs (l = 1.17 mm) quantum well diode lasers

Abstract—This letter reports studies on highly strained and strain-compensated InGaAs quantum-well (QW) active diode lasers on GaAs substrates, fabricated by low-temperature (550 C) metal–organic chemical vapor deposition (MOCVD) growth. Strain compensation of the (compressively strained) InGaAs QW is investigated by using either InGaP (tensile-strained) cladding layer or GaAsP (tensile-strained) barrier layers. High-performance = 1 165 m laser emission is achieved from InGaAs–GaAsP strain-compensated QW laser structures, with threshold current densities of 65 A/cm2 for 1500- m-cavity devices and transparency current densities of 50 A/cm2. The use of GaAsP-barrier layers are also shown to significantly improve the internal quantum efficiency of the highly strained InGaAs-active laser structure. As a result, external differential quantum efficiencies of 56 % are achieved for 500- m-cavity length diode lasers. Index Terms—Diode lasers, epitaxial growth, InGaAs–GaAs quantum well, long-wavelength lasers, quantum-well lasers, semi-conductor growth, semiconductor lasers, strain. I