Submilliampere-threshold 1.5- mu m strained-layer multiple quantum well lasers

The effect of high-reflection facet coatings on strained-layer multiple-quantum-well lasers was studied and submilliampere-threshold lasers were made in the 1.5- mu m wavelength region with a short cavity and high-reflection-coated facets. As a result of the compressive strain, the threshold current density is loss-limited instead of transparency-limited. By the use of the step-graded-index separate confinement heterostructure to reduce the waveguide loss, a threshold current density of 550 A/cm/sup 2/ was measured on 30- mu m wide broad area lasers with 1-mm long cavity.<
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