The Photonic Amplifier is a device designed by Howard Stark able to alter the behavior of the waves that compose the light.
Leviathan was able to obtain the blueprints for the Photonic Amplifier in the black market, a device designed by Howard Stark and deemed too dangerous to be sold. In order to build the weapon, Leviathan captured an engineer named Nikola and imprisoned him with Doctor Ivchenko, a psychiatrist, in the bottom level of the Red Room Academy.
Leviathan ordered Nikola to build the weapon, capturing his family as leverage, but Nikola died during an escape attempt before he could finish the weapon.
The blueprints were given to Roger Dooley of the Strategic Scientific Reserve; during his interrogation of Ivchenko, Dooley tried to learn more about the weapon, but Ivchenko said he was a psychiatrist, not an engineer.