Ultraviolet lasers (UV lasers) operate at 355nm. Despite generating little to no heat (i.e., cold marking), they can produce high-contrast marks on a variety of sensitive materials, including glass, ceramics, and plastics.
UV lasers can easily create marks without displacing or damaging materials which makes them popular in the medical and electronics industries where many applications require marking delicate materials and keeping parts sterile. Regardless of the industry though, UV lasers are great for any application that involves marking sensitive materials.