Molybdenum is the clear choice for general purpose CO₂-laser mirror substrates. It is the most durable with comparison to silicon and copper and is recommended for industrial environments where dirt and dust can cause severe problems with other types of mirrors. Molybdenum features high reflectivity, low thermal expansion and extreme hardness. The reflectivity of uncoated molybdenum is quite high at 10.6 mcm (>98%), and these mirrors are offered coated and uncoated. Uncoated molybdenum mirrors represent the best choice for applications where ultimate reflectivity is not paramount, but where durability is. Uncoated molybdenum is a fairly durable surface and can withstand considerably more rigorous cleaning than silver reflective coating having protection.

The following products from Mo are available: