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