A photonic disruptor was a type of ship-mounted weapon utilized by the Lokirrim, a species in the Delta Quadrant, which was at war with photonic lifeforms. The weapon operated by generating a disruption field which acted to decompile the matrix of a targeted hologram.
In 2377, a Lokirrim vessel used its photonic disruptor on the Delta Flyer, after detecting The Doctor on board. Suspecting him of being a photonic insurgent, they attempted to decompile him, but Seven of Nine was able to download his program into her cybernetic matrix. The Lokirrim later attacked the USS Voyager with the same weapon, when it detected photonic activity on one of its holodecks. (VOY: "Body and Soul")