Sub-milliampere operation of 1.55 µm wavelengthhighindex-coupled buried heterostructure distributed feedback lasers

Abstract

Sub-milliampere operation was realised in 1.55 µm wavelength high index-coupled buried heterostructure distributed feedback (BH-DFB) lasers consisting of deeply etched double-quantum-well wirelike active regions. A threshold current Ith as low as 0.7 mA and an external differential quantum efficiency of 23%/facet were obtained for a cavity length of 200 µm with cleaved facets and a stripe width of 2.3 µm.