Nonclassical correlations and entanglement in intracavity second harmonic generation

Quantum information science is a rapidly growing field of research that combines the techniques developed in quantum optics with those of information science. One primary goal of the field is to implement a quantum information network using non-classical light sources such as entangled photon pairs. The process of parametric down conversion has been widely used to generate entangled photons as well as twin beams that have intensity correlations below the shot noise limit. The complementary process - second harmonic generation (SHG) is less well studied in comparison. This dissertation presents the techniques of generating non-classical optical fields using SHG in the continuous variable regime of quantum mechanics.; Using a potassium niobate crystal in a resonator, bright blue light was generated through frequency doubling of an infrared beam. We report an observation of 1 dB noise reduction in the amplitude fluctuations of the harmonic output. By double-passing the nonlinear crystal sitting inside a resonator, we set up a singly resonant system which allows two harmonic beams to escape at two different ports. Using a self-consistent propagation model and solutions of the traveling wave SHG, we show that such a dual ported cavity can be used to generate entangled beams with nonclassical intensity correlations in the harmonic outputs. We obtain 0.9 dB of twin-beam intensity correlation from the resonator and demonstrate the inseparability of the two beams with a balanced Mach-Zehnder interferometer.; In addition to the generation of quantum correlated states of light, we also investigate the dynamic of coherent light in SHG such as the generation of optical vortices. We demonstrate generation and frequency doubling of unit charge vortices in a linear astigmatic resonator. Through an appropriate alignment of a near confocal cavity, we couple higher order transverse modes of the fundamental laser beam into a vortex mode. With the presence of a nonlinear crystal, a doubly charged vortex was generated. Topological instability of the double charge harmonic vortices leads to well separated vortex cores that are shown to rotate, and become anisotropic, as the resonator is tuned across resonance.