Gravity laser

A gravity laser (or gaser) is a device for stimulated emission of coherent gravitational radiation or gravitons, similar to a laser which produces coherent electromagnetic radiation.

Conditions that must be met to build the device:


 * There must be particles in an excited state capable of emitting radiation at the desired frequency.
 * These particles must couple to supplied radiation in order to provide stimulated emission, possible using the Penrose process.
 * More particles must be in an excited state than the ground state
 * The lasing medium must be long enough for the radiation to persist and remain excited.

Uses:


 * propelling objects into space
 * weaponry

Example:

In David Brin's Earth: While attempting to remove micro singularities inadvertently introduced into the planetary mantle, it is found they can serve as mirrors, and the resulting gaser beams are used to nudge the singularities somewhere safer.