The thesis consists of theoretical and experimental studies on characteristics of the laser diode under optoelectronic feedback, as well as a new analytic treatment of solitary laser diode dynamics. As applications of these studies, we realize a new optical short-pulse generator and optical multistable devices that may be useful in high speed optoelectronic signal processing. Large signal modulation response, relaxation oscillation, bistability, period doubling routes to chaos, and self-pulsing in both the solitary laser diode and the laser diode under optoelectronic feedback are also investigated in detail. Understanding dynamic behavior of the solitary laser diode is fundamental to studies of the laster diode under optoelectronic feedback. It is well known that dynamics of the laser diode is critically dependent on spontaneous emiccion, gain saturation, Auger recombination, and saturable absorption. For the analytic treatment of the solitary laser diode that takes into account these effects, we transform the nonlinear rate equations and use a standard perturbation theory, i.e. the method of multiple scale expansions. Phenomena covered here include resonace frequency shift, relaxation oscillations, bistability, and period doubling bufurcations in a directly modulated laser diode. Based on this analytic treatment, we also explain mechanism of period doubling route to chaos in a directly modulated laser diode. Furthermore, we derive analytically the basic limit of optical pulse width that can be achieved from gain-switching of the solitary laser diode. To overcome some of this limit and to explore new device configurations, we seek utilization of optoelectronic feedback. We model the laser diode under optoelectronic feedback by using a rate-equation formulation. The optoelectronic feedback that has a negligible feedback time delay may be divided into two, i.e. the positive and the negative feedback. It is well known that the laser diode under positive optoelectr...