Multicore microstructure fibers have emerged as promising components in ultrahigh capacity transmissions, biomedical imaging, quantum computing and signal-processing applications like wavelength conversion, and optical amplification. For long-haul transmission they are attractive due to low differential group delay and nonlinear impairment reduction depending on the number of cores. In this thesis we explore the linear-optical and nonlinear-optical properties of single and triple-core microstructure fibers with the goal of using them in parametric devices based on the four-wave mixing (FWM) nonlinearity Although the presence of multiple cores in a fiber produces drawbacks as well as advantages, we experimentally demonstrate that FWM and parametric oscillation are possible in multicore microstructure fibers. One such advantage is the ability to increase the power conversion efficiency of a fiber optical parametric oscillator (FOPO). We also present results for a FOPO built using a single-core microstructure fiber and demonstrate a higher power extraction using a polarization-based output coupling method compared with a polarization-independent method.

We discuss measurements of the group velocity dispersion over a wavelength range from 1064-1600 nm. We study the mode coupling among the cores as a function of input power, polarization, wavelength, and spectral broadening. We demonstrate FWM in a triple core microstructure fiber at 1064 nm and study the transition between the case where FWM happens primarily in a single core and the case where FWM is distributed among multiple cores. We find that the effective nonlinear coefficient is reduced by a factor of 3 (the number of cores) when the coupling length is short compared with the nonlinear length, and that this leads to a three-fold reduction in the FWM bandwidth.