APPLICATION OF THE DIGITAL ALLOY COMPOSITION GRADING TECHNIQUE TO STRAINED INGAAS/GAAS/ALGAAS DIODE-LASER ACTIVE REGIONS

Molecular-beam epitaxy (MBE) growth, lasing performance, and transmission electron microscopy (TEM) of In0.25Ga0.75As asymmetric triangular quantum well (ATQW) active regions is reported. The digital alloy technique was utilized to form three active regions of widths 200, 300, and 400 angstrom. Each structure lased with a threshold current density of 313, 152, and 241 A/CM2, respectively. The lasing wavelength range was 979-1030 nm. This is the first demonstration that controlled, digitally graded quantum wells can be incorporated into laser diode active regions.