Formation of InAs1-xSbx quantum dots on vicincal InP(001) for 1.55-μm DFB laser applications

We have investigated the MOVPE growth of InAs1-xSbx quantum dots (QDs) on vicinal InP(0 0 1) substrate for DFB laser applications. Miscut orientation was adopted toward the [110] direction in which InAsSb quantum wires elongate on normal InP(0 0 1) substrate. The interval between the QDs and the lateral size of the QDs in the [1 1 0] direction decreased as the Sb fraction was increased, which brought the density to as high as 1.1 x 10(11) cm(-2) of InAsSb QDs. The InAsSb QDs were stacked with 30-nm-thick InGaAsP spacer layers for 10 periods without correlation, and had an emission of a wavelength at around 1.55 mu m although the segregation of Sb atoms was slightly observed, A pn-buried-heterostructure-type DFB laser with InAsSb-QD active layer was fabricated. The lasing wavelength was 1540.6 nm at 25 degrees C, and CW, single-mode lasing operation was demonstrated up to 100 degrees C. (c) 2008 Elsevier B.V. All rights reserved.