Multiwavelength and nonuniform laser beam calculations

Multiwavelength laser systems with nonuniform beams pose multiple challenges for the laser safety officer. Each wavelength might not exceed its maximum permissible exposure individually, but the laser may still pose a hazard collectively. ANSI Z136.1 briefly shows an example of a multiwavelength hazard calculation [American National Standards Institute, American National Standard for Safe Use of Lasers ANSI Z136.1 (ANSI, Washington, DC, 2022)]. We use the principles shown in that example to develop a hazard ratio Χ (Chi) for our multiwavelength hazard calculation technique. This intuitive technique is applicable for both ocular and skin hazard evaluations and simplifies the maximum exposure duration and minimum exposure distance calculations. Additionally, for a multiwavelength laser that also has a nonuniform beam, the power from each wavelength might not be distributed evenly within the overall beam shape. This requires additional measurement techniques. We approach these nonuniform beam measurements with a beam profiling camera and a set of bandpass filters. This paper will discuss a multiwavelength laser system with a nonuniform beam in use at Edmund Optics. We will cover how we used the above Χ calculation and aperture measurement techniques to quantify the potential hazards and determine optical densities for laser protective eyewear. We will also discuss how we worked with the primary users to determine and implement the appropriate controls to keep both users and bystanders safe.