Optical properties of columnar InAs quantum dots on InP for semiconductor optical amplifiers

Optical properties of polarization-controlled columnar quantum dots (QDs) grown by metalorganic vapor-phase epitaxy for semiconductor optical amplifier (SOA) applications are reported. The photoluminescence peak wavelength and polarization sensitivity depended on the time of AsH3 preflow before InAs growth as well as the InAs supply amount, and these changes in the optical properties are considered to be attributed to the change in the strain rather than the change in the height of the columnar QDs. Nearly polarization-insensitive QDs in the 1.5 μm region were obtained by 13-fold columnar QDs and finely controlling polarization of columnar-QD SOAs was demonstrated by changing barrier thickness by 0.05 ML steps.