Most CO2 lasers usually operate at 10.6µm. 10.6µm is good for cutting a variety of metal materials and non-metal materials. However, other industrial laser applications -- such as plastics processing -- need a specific wavelength band for maximum production efficiency.
Our band-selective cavity optics can effectively “lock” a CO2 laser to a specific wavelength for the specialized applications, such as 9.3µm wavelength for PCB drilling and plastics marking.
CO2 laser cavity includes: one type is the traditional stable cavity (output coupler, rear mirror and fold mirrors); the other type is the unstable cavity ( output mirrors and rear mirror).  
Selective wavelengths are typically: 9.3µm,  9.6µm,  10.2µm,  10.6µm