The purpose of this dissertation work is to improve two applications of tunable light sources with fiber optical parametric oscillators based on microstructure optical fibers: CARS microscopy and single photon sources. Microscopy of live cells is a vigorous area of research and is mostly enabled by fluorescent labeling of molecules of interest. While fluorescence microscopy has facilitated a vast number of biological discoveries, there are drawbacks to adding labels to the live environment. Coherent Raman scattering spectroscopy techniques probe the low frequency nuclear vibrations of materials using high frequency fields in a label-free manner. Owing to the label-free chemical specificity of the technique, the development of a lightweight, easy-to-use light source for coherent Raman scattering spectroscopy has a suite of implications for advancing biophotonics, clinical photonics, atmospherics and space exploration. CRS techniques require dexterous wavelength tuning in order to probe the wide variety of vibrational modes relevant to cell biology. We explore the benefits of fiber optical parametric oscillators as tunable light sources for CARS microscopy, namely the output power through polarization management and intensity noise characteristics. On the other side of the power scale, we explore the potential application of fiber parametric devices to improving single photon light sources. Fiber based platforms, which utilize spontaneous four-wave mixing (SFWM), present a potential simplification in the generation of correlated photon pairs over their solid-state counterparts that are based on spontaneous parametric down conversion (SPDC). This is primarily because SPDC sources require extensive filtering to perform efficient heralding. Fiber based systems can provide a dexterous tuning of entanglement properties for quantum information applications. We propose a characterization study of correlations between various output regimes in a fiber-based correlated photon pair source.