Voyager uses a beam of warp particles to illuminate a breach in the event horizon of a type-4 quantum singularity
Warp particles are the constituent quantum components of an energy form which can be produced by a vessel's warp engines.
In 2371, after having become trapped within the event horizon of a type-4 quantum singularity, the crew of the USS Voyager utilized warp particles to illuminate a breach in the horizon which they created when they initially entered the phenomenon. Locating the breach, they were able to safely exit through it and escape the singularity's gravitational influence. (VOY: "Parallax")