Many laser operations, especially in research applications, involve Class 3B and Class 4 beams of multiple wavelengths. Protective eyewear for the accessible laser beams can then pose a significant challenge, especially if these wavelengths span a significant portion of the 400-700 nm visible spectrum. The Laser Safety Officer must perform a good hazard evaluation to determine the best combination of engineering, administrative and PPE (personal protective equipment) controls to ensure there is an acceptable level of risk for the laser workers. This evaluation has to employ a hazard controls hierarchy, which gives highest priority to engineering controls.
Examples of multi-wavelength operations include: multiple laser sources; tunable OPAs, OPOs, and OPCPAs; and “white light” continuum lasers. Engineering, administrative and PPE controls for some examples of these are discussed. Full protection laser eyewear should be used for accessible laser beams, but considerations for alignment eyewear and remote operation are also needed.