Abstract: A laser gain element including an undoped layer of a monoclinic double tungstate (MDT) crystal, and a method of forming a laser gain element are provided. The laser gain element includes a layer of doped MDT crystal adjacent to the undoped layer, the doped MDT layer including a pre-selected concentration of rare earth ions. The layer of doped MDT crystal has an absorption peak at a first wavelength and an emission peak at a second wavelength longer than the first wavelength; and the layer of doped MDT crystal has a fluorescence emission with a weighted average at a third wavelength shorter than the first wavelength. A laser resonator cavity formed with a plurality of composite gain elements as above is also provided.

Abstract: A laser gain element including an undoped layer of a monoclinic double tungstate (MDT) crystal, and a method of forming a laser gain element are provided. The laser gain element includes a layer of doped MDT crystal adjacent to the undoped layer, the doped MDT layer including a pre-selected concentration of rare earth ions. The layer of doped MDT crystal has an absorption peak at a first wavelength and an emission peak at a second wavelength longer than the first wavelength; and the layer of doped MDT crystal has a fluorescence emission with a weighted average at a third wavelength shorter than the first wavelength. A laser resonator cavity formed with a plurality of composite gain elements as above is also provided.

Abstract: In accordance with the present invention, a crystal laser material that is suitable for self doubling is presented. A crystal according to the present invention includes a stoichiometric lithium niobate crystal isomorph host material doped with at least one laser ion. In some embodiments, the stoichiometric lithium niobate crystal isomorph host material is lithium niobate. In some embodiments, the stoichiometric lithium niobate crystal isomorph host material is lithium tantalate. In some embodiments, the at least one laser ion includes Ytterbium. In some embodiments, the at least one laser ion includes a rare-earth ion. In some embodiments, the stoichiometric lithium niobate crystal isomorph host material is periodically poled to provide quasi-phase matching. Additionally, further dopant ions, for example Magnesium, can be included.

Abstract: In accordance with the present invention, a crystal laser material that is suitable for self doubling is presented. A crystal according to the present invention includes a stoichiometric lithium niobate crystal isomorph host material doped with at least one laser ion. In some embodiments, the stoichiometric lithium niobate crystal isomorph host material is lithium niobate. In some embodiments, the stoichiometric lithium niobate crystal isomorph host material is lithium tantalate. In some embodiments, the at least one laser ion includes Ytterbium. In some embodiments, the at least one laser ion includes a rare-earth ion. In some embodiments, the stoichiometric lithium niobate crystal isomorph host material is periodically poled to provide quasi-phase matching. Additionally, further dopant ions, for example Magnesium, can be included.

Abstract: A new photorefractive material comprises BaTiO.sub.3 double-doped with two dopant species, both of which have at least two valence states, with one of the dopant species (e.g., cerium) having an ionization level that is near the middle of the barium titanate bandgap and the other dopant species (e.g., rhodium) having an ionization level that is closer to the valence band edge of barium titanate, such that both dopant species are sensitive to visible light, but only one dopant species (the one closer to the valence band edge) is sensitive to infrared radiation. The double-doped BaTiO.sub.3 provides a unique combination of photorefractive properties, thereby improving its performance as a holographic storage medium. The double-doped barium titanate crystal is employed as a holographic recording element. The double-doped barium titanate crystal has a dark storage time at room temperature of several years or more and may be nondestructively read out at an infrared wavelength.

Abstract: An optical amplification system directs a diffraction-limited signal beam through a series of crossings, at substantially less than 90.degree. crossing angles, with a number of non-diffraction-limited pump beams in a photorefractive medium. The pump beams are e-polarized while the signal beam travels down the crystal medium's c-axis and is polarized in the same plane as the pump beam polarization, resulting in an energy transfer from the pumps to the signal beam while leaving the signal beam diffraction-limited. The photorefractive medium is preferably a series of BaTiO.sub.3 :Rh crystals that are aligned parallel to the angled edge of a wedged-shape prism through which the pump beams are transmitted, with the crystals cut so that their C-axes are parallel to the signal beam.