A rod amplifier consists of a rod of laser glass (Nd :glass) surrounded by as many flashlamps as possible.
The flash lamps fire and some fraction of the emitted light is absorbed by the laser medium. The energy absorbed will be stored in the laser glass until the laser pulse comes along, in much the same way a capacitor stores electrical energy. As the pulse travels through the rod it gains energy from the medium. By the time the pulse from any of the oscillators reaches the end of the rod chain it will have a few Joules of energy.
There are two complete rod chains on Vulcan. The simplest rod chain is composed of a 16 mm diameter rod amplifier, a 25 mm diameter rod amplifier and a 45 mm diameter. The second chain can use an additional 45 mm amplifier.
