The field of non-linear optics has grown rapidly over the last 50 years, thanks to the discovery of innovative techniques of Phase Matching such as Quasi-Phase Matching (QPM). The Optical Parametric Oscillators (OPOs) are the result of this trend and are intended to supplement the ordinary laser light sources, due to their versatility and tunability. This project aims to illustrate the implementation of an Ultrafast Optical Parametric Oscillator tunable from 1000nm to 1400nm: starting from the design of the cavity, passing through the construction of the source until its application. This project has as its main motivation to realize a source tunable in the visible for time-resolved photoluminescence measurements. The design of this source has been realized in collaboration with a research group of the Heriot-Watt University in Edinburgh, specialized in the production of Ultrafast Optical Parametric Oscillators. This book is a good introduction to the basics of non-linear parametric devices.