The Epitaxial Growth Of InAs QD And The Effect Of Two-Electrode SOA On The Bit Error Of Optical Signal Transmission

Semiconductor optical amplifiers (SOAs) have many advantages, such as smallvolume, low cost, being easy to be integrated with other semiconductor devices and so on.SOAs show good performance on optical signal amplifying, optical signal processing andoptical signal exchange, they will be key components in the next generation optical fibercommunication systems. However, at present, bulk SOAs and quantum well SOAs as themain commercial production can’t meet the need of the all-optical network. So we need toseek new semiconductor nanostructures to make SOAs. Quantum dots (QDs) and quantumdot molecules (QDMs) have good physical and chemical property. They have attractedconsiderable interest and have been studied intensively in optoelectronic deviceapplications. In this thesis, we investigate the structural and optical properties of the QDsand QDMs grown by metal-organic chemical vapor deposition (MOCVD). We alsoperform experiments about the effect of two-electrode SOA on the bit error of opticaltransmission. The main contents are summarized as follows:1、V/III ratio plays an important role in QD density, QD size distribution andphotoluminescence(PL). To some extent, as V/III ratio increases, the density of QDsdecreases accompanied by the transition of QD size distribution from bimodal tosingle-modal, and then to bimodal again. PL intensity decreases.2、A kind of step structure is formed on the growth surface of misoriented substrate.The step density and width affect QD density and size respectively. The effect ofmisoriented substrate on single-layer QDs and multilayer QDs is different.3、QDMs are fabricated by MOCVD. Experiences prove that longer growth time andhigher growth temperature can boost QDs change into QDMs. Compared with PL of QDs,the PL of QDMs is wider and higher. 4、The bit error ratio(BER) of two-electrode SOAs has special characters: whensignal light is input from the long end, BER is dominated by gain saturation; when signallight is input from the short end, BER is dominated by gain saturation and noisefigure(NF).