| This dissertation focuses on exploring the interaction between confined photons and confined electronic states in new classes of semiconductor microcavities. We apply epitaxial and microfabrication technologies to make semiconductor microstructures that contain embedded nanostructures such as quantum wells and quantum dots. We use optical techniques, such as cryogenic static and dynamic microphotoluminescence, to study the physics of confined photons and confined electronic states in these systems.; The first set of experiments focus on ZnSe microdisks containing Zn 0.7Cd0.3Se quantum wells. Unlike the more extensively investigated microcavities based upon the III-V semiconductors, these wide band gap systems are expected to be characterized by stronger excitonic effects. We have developed new protocols for the consistent fabrication of ZnSe microdisks of high structural quality, supported on (Al,Ga)As pedestals. The photoluminescence emission spectrum is dominated by excitonic recombination in the quantum well region. We observe a set of sharp emission lines on the low energy shoulder of the quantum well photoluminescence. We attribute these features to the coupling between exciton emission and the whispering-gallery modes of the microdisk. This inference is consistent with our temperature-dependent measurements. However, power-dependent measurements of these microdisks did not produce any evidence for stimulated emission, even when excited at high optical intensities using pulsed excitation. We conclude that harmful surface recombination may be responsible for these observations.; The next set of experiments focus on the steady state and dynamic optical properties of GaAs/(Ga,Al)As microdisk containing interface fluctuation quantum dots. These constitute a departure from previously studied GaAs/(Ga,Al)As microdisk systems that contain self assembled quantum dots. We have developed a new processing protocol for fabricating these microdisks, including a surface passivation technique that greatly enhances the optical properties of these systems. Stimulated emission is achieved in the microdisk cavity using optical excitation. Steady-state measurements of the stimulated emission via whispering gallery modes yield a quality factor Q ∼ 5800 and a coupling constant beta ∼ 0.09. The broad gain spectrum produces mode hopping between spectrally adjacent whispering gallery modes as a function of temperature and excitation power. (Abstract shortened by UMI.)... |
