Rami Arieli: "The Laser Adventure"

Rami Arieli: "The Laser Adventure" Chapter 6, Argon Gas Lasers, page 2

Output Power from Argon Laser
The gain of the active mediumin Argon ion lasers is very high, so high power can be achieved from Argon ion lasers (tens of Watts), although as we saw, with low efficiency.

The output power increases as a nonlinear function of the current density in the tube. Thus it is common to use narrow tubes (small cross section) and very high currents (100-500 [A/cm²]). Argon Ion lasers require a separate three phase electrical power lines.

The ignition of the Argon Ion laser is done by a pulse of high voltage (about 10 Kilovolts DC) ionizes the argon gas.
After ionization, a few hundreds volts DC are maintained across the laser tube.
A high DC current (more than 50 Ampers) maintains lasing (For more technical detail click here).

Such high current densities create large amounts of heat which must be taken away from the laser. Argon Ion lasers require water cooling.

In order to withstand the high temperatures, the laser tube is made from special high melting materials such as Beryllium Oxide. This material has very high thermal conductivity, and is not destroyed by the electrical discharge.

The radiation of Argon Ion laser is hazardous to view (class 3b and higher), and working with it requires special protecting goggles for everyone in the room (See safety appendix).