In optics, the measure of the magnitudes is associated with the radiant energy in the optical interval of the electromagnetic spectrum (ultraviolet, visible and infrared) [1].One of the magnitudes associated to the radiation is the quantity of energy transported and for multiple reasons it is necessary to carry out measurements of radiant energy with higher precision and accuracy. This necessity has impelled the most precise and exact search of measuring system [2]. The rapid development of picosecond, femtosecond and attosecond technology has allowed us to examine fundamental process in materials. To accurately determine an interval of short duration, one must first be able to measure its duration. One measuring technique is to identify events that recur regularly over and over again, such as the passing of a day. The ancients knew how to subdivide time by using devices such as sundials. For measuring still shorter time intervals, they used the hour glass or allowed a specific quantity of water to drip from cistern. However, they apparently showed no interest in studying physical events with these methods [3]. Much of the ground work for picosecond light pulse technology was laid by related discoveries during the five years preceding the use of high power modelocked lasers. All main lasers now used for picosecond work were discovered during this period: the ruby, Nd:glass, Nd YAG, and dye lasers [4]. Besides the discovery of lasers in this five years period, many nonlinear optical effects were detected, some of which were shortly to become an integral part of picosecond techniques, e.g. second and third harmonic generation [5].