Other laser - related hazards

Any laser source needs a primary energy source responsible for the population inversion on which laser (stimulated) emission relies. For most of the lasers, this source is electric. Of course, some lasers are optically pumped, either by another laser (for example, Argon laser is commonly used to pump Titanium-doped Sapphire lasers), or by other light sources (flash lamps). In any case, electric energy comes as the original source.

The mean conversion efficiency of laser sources, from electric power to optical power, is low (typically a few 10%). To illustrate this, one can look at the example of Argon laser, delivering an optical power of up to a few tens Watts continuously. The electric pumping source delivers a few hundreds Watts, and consequently presents some hazard to the laser user. Moreover, such laser sources commonly need a water-cooling system. One has thus to be extremely cautious in order to isolate the electric source from the cooling system.

There are different chemical hazard types:

• The first one can be directly related to the laser, and more specifically to its amplifying medium. Indeed, inside the wide spectrum of laser sources, there are very different mediums. Solid mediums lead to moderate hazard. Liquid mediums (used for example in dye lasers) are generally very toxic, and special care must be taken to prevent any contact between the medium and the skin. Finally, gaseous mediums lead to moderate hazard as the gas is confined inside a hermetically closed tube. Thus, one mainly needs to be cautious during maintenance operations.

• The second one is related to the exposition of materials to laser radiations in order to voluntarily trigger chemical transformations. These activities can create some chemical pollution. Indeed, the layers on the surface of these materials (corrosion protective layer, stain removal solvents), when exposed to high intensity optical fields, can be damaged by thermal effects and emit toxic gases.