Input Power. Dye lasers pumped by an external laser have modest electrical power requirements because the external light generates the beam. However, power is needed for optical and electronic controls, dye solution pumps, and other equipment. Data sheets for some low-power dye lasers do not mention electrical power requirements, and some such lasers may not need electrical power. Others, especially those operating at higher powers or pumped by a continuous-wave laser, need modest electrical power for dye-circulation pumps, computer controls, or other equipment. All pump lasers need electrical power; their requirements are described in other chapters.

Flashlamp-pumped dye lasers do need significant electrical power to drive the flashlamp that pumps the dye. The power supply stores electrical energy, which it discharges through the flashlamp to produce the pulse of light which excites the dye. Power requirements range from 15 amperes (A) at 110 volts (V) to 100 A at 208/220 V. Linear flashlamps often are driven with a simmer power supply, which keeps a moderate current flowing through the tube between pulses. This current is not sufficient to generate light, but does preionize the gas, increasing output and decreasing pulse rise time. Coaxial flashlamps cannot be operated with a simmer power supply because the low current does not flow uniformly through the annular lamp.

Cooling. Flashlamp-pumped dye lasers typically remove excess heat by flowing water through the system at rates to 20 liters per minute (L/min). (Slower flows are more typical.) The water...