This thesis focuses on the design parameters of waveguides and ring resonators to generate photon pairs through the four-wave mixing process. The goal was to design these components specifically for generating visible-range photon pairs with the intention of using visible-range photodetectors. These detectors offer a better photon detection range, lower dark count, and faster response time compared to their telecom-range counterparts. Additionally, visible wavelength photons are more effective in free-space communication. A photonic platform, such as a Si3N4 waveguide or a ring resonator on a SiO2 layer, is utilized for photon pair generation due to several advantages. These advantages include the ability to leverage CMOS technologies and operate at room temperature. The choice of Si3N4 material aims to avoid a two-photon absorption process. Compared to Si-based sources, which exhibit a two-photon absorption process due to their band energy, utilizing Si3N4 helps circumvent this issue. In this thesis, the dimensions of the waveguide are tailored to satisfy the phasematching condition, and its dispersion properties are studied. A ring resonator is constructed based on determined dimensions, and its spectral characteristics are analyzed for efficient photon pair generation.