1. How Each Laser Type Works

Fiber Laser (1064nm)

A fiber laser generates its beam inside an optical fiber doped with ytterbium ions. Pump diodes excite the ytterbium, which emits at 1064nm. The beam stays inside the fiber until it exits through a collimator, meaning there are no mirrors or alignment to maintain.

Key characteristic: 1064nm is in the near-infrared range. Metals absorb this wavelength well because their free electrons interact strongly with photons at this energy level. Most organics and transparent plastics are largely transparent to 1064nm.

CO2 Laser (10.6μm)

A CO2 laser excites a gas mixture of carbon dioxide, nitrogen, and helium inside a glass tube or RF-excited chamber. The excited CO2 molecules release energy at 10.6μm — deep in the mid-infrared range.

Key characteristic: 10.6μm is strongly absorbed by materials containing water, carbon, and oxygen bonds — essentially all organic materials. Metals, however, reflect ~95%+ of this wavelength, making bare metal marking nearly impossible without a marking compound.

UV Laser (355nm)

A UV laser starts with an infrared source and passes it through nonlinear crystals (frequency tripling) to produce 355nm output. This is in the ultraviolet spectrum.

Key characteristic: 355nm photons carry higher energy than infrared photons, enabling direct bond-breaking in polymer molecules (photochemical effect) rather than relying solely on heat. This is why UV marking produces minimal thermal damage — it’s often called “cold marking.”