Different types of materials and associated parameters
Passive saturable absorbers for short-pulse lasers

There are various types of saturable absorber materials and devices with a wide range of parameters that can be used to achieve "passive" Q-switched or mode-locked laser operation, some of which are more suitable for one mode of operation than the other.

Among these different materials, the three most important categories are :

• transparent crystals and ceramics based on dielectric or semiconductor materials doped with transition ions from the iron group ;

• semiconductor-based mirror structures known as SESAM ,

• nanomaterials in thin-film or nanoparticle form (quantum dots) based on semiconductors doped or not by defects.

That said, because of their optical and dynamic characteristics, but also their damage thresholds,...