Abstract: Inorganic crystals having one or more species of dopant ions which are photo-reactive are used as visible and or infrared light optical limiters to protect against laser radiation exposure while permitting passage of the visible and or infrared light spectrum at least until exposed to high energy laser radiation. The dopant ions are selected from ions of transition metals. The exposure of these ions within the transparent crystalline matrix either photo-ionize or are elevated to an excited state and thereby absorb or otherwise attenuate the passage of the laser beam radiation sufficiently to protect human eyes or photo-sensitive equipment. The crystals may be fabricated into such items as lenses for use in eyeglasses or on shields of flight helmets to protect the eyes of aircraft pilots.

Abstract: Inorganic crystals having one or more species of dopant ions which are photo-reactive are used as visible and or infrared light optical limiters to protect against laser radiation exposure while permitting passage of the visible and or infrared light spectrum at least until exposed to high energy laser radiation. The dopant ions are selected from ions of transition metals. The exposure of these ions within the transparent crystalline matrix either photo-ionize or are elevated to an excited state and thereby absorb or otherwise attenuate the passage of the laser beam radiation sufficiently to protect human eyes or photo-sensitive equipment. The crystals may be fabricated into such items as lenses for use in eyeglasses or on shields of flight helmets to protect the eyes of aircraft pilots.

Abstract: Inorganic crystals having one or more species of dopant ions which are photo-reactive are used as visible and or infrared light optical limiters to protect against laser radiation exposure while permitting passage of the visible and or infrared light spectrum at least until exposed to high energy laser radiation. The dopant ions are selected from ions of transition metals. The exposure of these ions within the transparent crystalline matrix either photo-ionize or are elevated to an excited state and thereby absorb or otherwise attenuate the passage of the laser beam radiation sufficiently to protect human eyes or photo-sensitive equipment. The crystals may be fabricated into such items as lenses for use in eyeglasses or on shields of flight helmets to protect the eyes of aircraft pilots.

Abstract: A method is provided to control the lasing wavelength of a laser material without changing or adjusting the mechanical components of a laser device. The rate at which the laser material is pumped with the pumping energy is controlled so that lasing occurs at one or more lasing wavelengths based on the rate. The lasing wavelengths are determined by transition lifetimes and/or energy transfer rates.

Abstract: A quasi four-level solid-state laser is provided. A laser crystal is disposed in a laser cavity. The laser crystal has a LuAG-based host material doped to a final concentration between about 2% and about 7% thulium (Tm) ions. For the more heavily doped final concentrations, the LuAG-based host material is a LuAG seed crystal doped with a small concentration of Tm ions. Laser diode arrays are disposed transversely to the laser crystal for energizing the Tm ions.