The laser safety class covering continuous lasers above 0.5 W and pulsed lasers above the Class 3B limits. Direct, specular and diffuse reflections can all injure the eye, the beam can burn skin and ignite materials, and the controls follow: a laser safety officer, controlled area with interlocked doors, warning lights, beam enclosures, eyewear rated for every wavelength present and written procedures.
Room's posted Class 4 when the amplifier's on, so lights on outside the door, eyewear on, no watches or rings.
Also heard as
- Class IV
- class four
Related terms
Goggles
Lab shorthand for laser safety eyewear, the filtering glasses or goggles rated by optical density at specific wavelengths.
OD
Optical Density: a logarithmic measure of how strongly a filter or laser eyewear blocks light at a given wavelength.
Glint
A brief, bright reflection of a laser beam off a shiny object such as a tool, screw head, mount or jewelry.
Beam dump
A device that absorbs an unwanted or terminated laser beam completely and safely, without reflecting it.