Quantum Confined Stark Effect

In this work, the feasibility of a monolithically integrated laser and electroabsorption modulator based on the same active quantum dot epistructure is studied. The net modal gain and the absorption in the modulator were measured using the segmented contact method from 25 °C to 125 °C. The maximum of the net modal gain active region of the laser decreases from 10 cm -1 at 25 °C to 3.9 cm -1 at 125 °C. The non-optimized maximum extinction ratio of the modulator, 4.1 dB·mm -1 , is almost constant until 25 °C. The wavelengths at which the net modal gain and the change in absorption are maximum shifts with temperature by 0.04 eV.

The two main objectives of this dissertation are the systematic development of explicitly correlated electron-hole wave function based methods and the application of these methods to chemical systems with an emphasis on nanoparticles. The understanding of the basic physics of excited electronic states is an important consideration when developing new methods and applications. In this dissertation, excited electronic states were studied using the electron-hole quasiparticle representation. Theoretical treatment of electronic excitation in large quantum dots and nanoparticles is challenging because of the large number of electrons in the system. The quasiparticle representation provides an alternative representation that can partially alleviate the computational bottleneck associated with investigating these systems. However, in this representation, the effects of electron-hole correlation must be understood in order to accurately describe the system’s optical and electronic propertie...