Abstract

A new laser structure, the strip buried heterostructure (SBH) laser (Fig. 1(a)), is described and tested. In this structure, the thin active p-GaAs layer (~0.2 μm) is present in the form of a narrow strip with widths of ~2.5 μm - ~10 μm grown on top of an N-Al_0.3Ga_0.9As planar layer of thickness ~1 μm - ~1.5 μm. This combination constitutes’a strip optical waveguide which is contained between the usual P-Al_0.3Ga_0.7As and N-Al_0.3Ga_0.7As cladding layers. Lateral current injection confinement is accomplished by a single top built-in reverse-biased n-p junction¹,²,³ Low current threshold is achievable in this laser because the active p-GaAs is kept thin (<0.2 μm) and because carrier diffusion out of the active strip is limited by the surrounding N-Al_0.1Ga_0.9As and P-Al_0.3Ga_0.7As layers. There is still appreciable current spreading. However, it should be possible to reduce current spreading with more effective lateral current injection confinement schemes.³

© 1978 Optical Society of America