A Dominion ship fires a phased polaron beam  


Starfleet's first encounter with the Dominion's phased polaron beam was a costly one. No matter what shield frequency nutation was used, the beam cut through as if the shields were nonexistent. This necessitated the Galaxy-class U.S.S. Odyssey to lower her shields and divert all power to weapons. The Odyssey was eventually destroyed during the battle.

The Phased Polaron Beam was still a mystery to Starfleet Science until Captain Benjamin Sisko captured a Dominion attack ship. The ship was examined to bow to stern and analyzed. Starfleet developed a countermeasure to the Phased Polaron Beam and was installed on Starbase Deep Space 9. The battle soon after proved the new shield system worked. This shield system was quickly installed on all commissioned Starfleet starships.