Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm?1 and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: The present invention relates to a solid state laser device with a solid state gain medium between two resonator end mirrors (3, 5) and a GaN-based pump laser (1) arranged to optically pump the solid state gain medium. The solid state gain medium is a Pr3+-doped crystalline or polycrystalline host material (4) which has a cubic crystalline structure and highest phonon energies of ?600 cm and provides a band gap of ?5.5 eV. The proposed solid state laser can be designed to emit at several visible wavelengths with the emitted power showing a reduced dependence on the temperature of the GaN-based pump laser (1).

Abstract: Mixed silicates of yttrium and lanthanide and laser using monocrystals of these silicates. The laser has a laser cavity (2) containing as the light emitter a monocrystal (4), means (12,14) for amplifying the light from the monocrystal, means (14) for removing light from the laser cavity and optical pumping means (6), characterized in that the monocrystal is of formula (I):Y.sub.2-2x-2y M.sub.2x Yb.sub.2y SiO.sub.5 (I)in which M represents a lanthanide chosen from among erbium and thulium and x and y represent numbers such that 0<x.ltoreq.0.2 and 0<y.ltoreq.0.2.

Abstract: These lasers in particular have two flashlamps (30, 32) for longitudinally pumping a monocrystalline aluminate bar (28) emitting in the visible and near infrared, two mirrors (38, 40) for amplifying the light emitted by the bath, a polarizer prism (42) used for feeding the amplified light beam to the outside of the laser cavity. The magnetoplumbite-type aluminate has in particular the formula:La.sub.1-x Mg.sub.1-y-z Mt.sub.v Al.sub.11+x+2y/ 3-v O.sub.19-z(II)in which Mt represents a transition metal chosen from titanium and zirconium; x is a number such that 0<x<0.3; y and z are numbers such that 0.ltoreq.y+z.ltoreq.1 with 0.ltoreq.y.ltoreq.1 and 0.ltoreq.z.ltoreq.1; v is a number such that 0<v<1.

Abstract: The invention relates to a novel oxide for tunable lasers. These oxides comply with the formula:(A.sub.1-x X.sub.x).sub.n (B.sub.1-y Y.sub.y).sub.m O.sub.4in whichA represents one or more elements chosen from the group Mg, Mn and Zn;X represents one or more optically active divalent cations chosen from among V, Ni and Co;B represents one or more elements of the same valence chosen in the group comprising Si, Ge, P, Te, W, Al, In, Ga and Mo;Y represents one or more optically active trivalent cations chosen from among Cr, V and Ni;x is such that 0.ltoreq.x.ltoreq.0.15;y is such that 0.ltoreq.y.ltoreq.0.15; andm and n are integers such that 2n+vm=8 with v representing the valence of B, provided that y=0 when B represents one or more elements chosen from among Si, Ge, P, Te, W and Mo and x and y are not both equal to 0.As an example of such oxides, reference is made to Mg.sub.0.99 Ni.sub.0.01 Al.sub.2 O.sub.