There can be two types of factors that “stimulated” the Age of Exploration. First, there can be factors that made Europeans want to explore. Second, there can be factors that made it possible for them to do so.
One reason why Europeans wanted to go exploring was economic. Europeans had been in contact with Asia from the time of the Mongol conquests until the 14th century. They had heard about the East through things like accounts of Marco Polo’s journeys. They had become very aware of the silks and spices and other things that came from the East. But then the Mongols were defeated by the Ming Chinese and the Ottoman Turks conquered the Byzantine Empire. This cut Europe off from Asian trade. Therefore, people like the Portuguese had a motive to start exploring for ways to get to Asia by sea.
One reason that the Europeans were able to go exploring was the growth of centralized monarchies during the Renaissance. When monarchs in Europe consolidated their power over an entire country, they came to have more resources. They also did not have to devote so many resources to fighting at home. This enabled countries like Portugal and Spain to have the resources to go exploring.
Finally, Europeans had developed technology that made exploration more possible. An example of this was the development of the caravel, which was a type of ship that was very seaworthy and suited for long voyages.
These factors, among others, helped stimulate the Age of Exploration.