Developing quantum devices with high generation rates, small sizes, and robust operation is a mandatory requirement in the research toward a fully working quantum network and quantum internet. The integration of light sources into photonic integrated circuits is a novel and promising approach to such a problem. In this thesis, we detail the generation and characterization of entangled states of light in an integrated Si3N4 microresonator. The goal is to develop on-chip single- and entangled-photon sources compatible with the telecom band, utilizing third-order nonlinearity. To provide a clearer characterization of the light generated by the microresonator, we first present a metrological study of the detection efficiency of SNSPDs.