Highlighted in this work are recent accomplishments in nanoparticle doping of high power fiber lasers operating at “eye-safer” wavelengths. Both erbium and holmium doped fiber lasers are attractive candidates for high energy lasers (HELs) used in directed energy applications because they operate at wavelengths that are both safer to the eye and in a high atmospheric transmission window. Diffuse and low intensity parasitic reflections from dust, aerosols, or the target itself can be focused onto the retina with a gain of >104 for wavelengths <1.4 µm [1]. Though technically not eye-safe due to the high powers employed, some degree of laser safety can be gained by operation at wavelengths >1.4 µm since the cornea, lens, vitreous- and aqueous-humor absorb the light and reduce the potential chance of retinal damage.
