Output Couplers

Ouput couplers are mainly used inside resonators to extract the laser beam. Through a suitable choice of the degree of reflection the quality of the laser resonator is optimized. Output couplers are also commonly used in attenuation. The back side of output couplers is typically equipped with an AR coating to minimize the loss of the transmitted beam.

Output Couplers for Excimer Lasers. For mirrors that are used outside of the excimer laser resonator, the standard coating is usually applied to fused silica substrates. If the mirrors are used inside the resonator, the coatings have to be chlorine or fluorine resistant because they are exposed to the aggressive laser gas. In such a case, it is important to use CaF₂ or MgF₂ as the substrate material.

Output Couplers for Solid-state Lasers. These coatings are primarily applied to BK7 substrates. For systems with very high power densities, the coatings can also be applied to fused silica.

Output Couplers for cw/fs Mirrors. These coatings are mainly applied to fused silica substrates. Some mirrors are also available on BK7 substrates. As an option, the rear side can be AR coated to prevent losses.