In this thesis work, we characterize lasers based on self-organized In(Ga)As quantum dots (QDs). Intrinsic static and dynamic lasing properties of QD lasers are surveyed in high performance devices with a variety of device geometry, cavity loss and QD gain system. At first, the carrier and gain processes are analyzed that affect the temperature dependence of QD lasers. The characteristic temper...

We investigated the ground-state (GS) modulation characteristics of 1.3 μm InAs/GaAs quantum dot (QD) lasers that consist of either as-grown or annealed QDs. The choice of annealing conditions was determined from our recently reported results. With reference to the as-grown QD lasers, one obtains approximately 18% improvement in the modulation bandwidth from the annealed QD lasers. In addition,...

III-Nitrides QD lasers are studied in detail. Two types of QD structures are considered, GaN/AlxGa1-xN/AlN and InxGa1-xN/ In0.04Ga0.96N /GaN. Effects of: QD size; QD and WL composition; and doping are studied through the calculations of gain, threshold current, and intensity modulation bandwidth. It is shown that GaN QDs are less sensitive to size fluctuations. Bandwidth increases with doping a...

the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...

The modulation response, relative intensity noise (RIN) and frequency noise (FN) characteristics of quantum dot (QD) lasers are investigated theoretically in the presence of an external optical beam. Using small signal analysis of the rate equations for carriers and photons, it is demonstrated that by injecting excess carriers into the QDs excited state through optical pumping, the modulation r...

InAs quantum-dot (QD) lasers were investigated in the temperature range 20–300 K and under hydrostatic pressure in the range of 0–12 kbar at room temperature. The results indicate that Auger recombination is very important in 1.3m QD lasers at room temperature and it is, therefore, the possible cause of the relatively low characteristic temperature observed, of 0 = 41 K. In the 980-nm QD lasers...

The three-dimensional confinement of electrons and holes in the semiconductor quantum dot (QD) structure profoundly changes its density of states compared to the bulk semiconductor or the thin-film quantum well (QW) structure. The aim of this paper is to theoretically investigate the microwave properties of InAs/InP(311B) QD lasers. A new expression of the modulation transfer function is derive...

Self-assembled GaInNAs quantum dots (QDs) were grown on GaAs (001) substrate using solidsource molecular-beam epitaxy (SSMBE) equipped with a radio-frequency nitrogen plasma source. The GaInNAs QD growth characteristics were extensively investigated using atomic-force microscopy (AFM), photoluminescence (PL), and transmission electron microscopy (TEM) measurements. Self-assembled GaInNAs/GaAsN ...

Ten-layer InAs/In0.15Ga0.85As quantum dot (QD) laser structures have been grown using molecular beam epitaxy (MBE) on GaAs (001) substrate. Using the pulsed anodic oxidation technique, narrow (2 lm) ridge waveguide (RWG) InAs QD lasers have been fabricated. Under continuous wave operation, the InAs QD laser (2 · 2,000 lm) delivered total output power of up to 272.6 mW at 10 C at 1.3 lm. Under p...