A solar sail was a propulsion device that reflected photons from a star in order to push an object.
Between the 16th and 21st centuries Bajoran lightships used solar sails as their primary means of propulsion. Inspired by these ships, Benjamin Sisko built a lightship, the Baraka, in which he took his son as a companion during a flight. (DS9 episodes: "Explorers", "Accession")
A Risian luxury cruiser was equipped with a solar sail Quantum slipstream drive. (ST video game: Star Trek Online)
The Spectre class ships used an ion glide solar sail for covert propulsion. (NF novel: After the Fall)
In 2020, Shaun Christopher recalled that solar sails were used aboard some of Earth's satellites to help maintain their orbit. (TOS novel: The Rings of Time)
In 2286, the USS Yorktown's chief engineer rigged a solar sail to provide power to the ship's life support after the Whale Probe disabled it. (TOS movie: Star Trek IV: The Voyage Home)
In 2364, Wesley Crusher suggested using a solar sail to escape from an alien creature without attracting its attention, but William T. Riker said that method would be too slow. (TNG novel: Ghost Ship)