They can be tuned by varying the applied current, temperature or magnetic field. Semiconductor laser diagram Gas lasers consist of a gas filled tube placed in the laser cavity as shown in figure 6. One should note that if brewster angle windows are attached to the gas discharge tube, some laser radiation may be reflected out the side of the laser cavity. Large gas lasers known as gas dynamic lasers use a combustion chamber and supersonic nozzle for population inversion. Figure 7 shows a dye laser diagram.
Dye lasers employ an active material in a liquid suspension.
The dye cell contains the lasing medium. Many dyes or liquid suspensions are toxic. Common Dye Laser Diagram Free electron lasers such as in figure 8 have the ability to generate wavelengths from the microwave to the X-ray region. They operate by having an electron beam in an optical cavity pass through a wiggler magnetic field. The change in direction exerted by the magnetic field on the electrons causes them to emit photons.