37 results about "Strontium fluoride" patented technology

The present invention relates to a device for optically measuring the temperatures of cryogenic fluids or of moving surfaces in such fluids by analyzing the decay in the luminescence of a doped crystal, the device comprising a light source for exciting said crystal, an optical fiber for transporting the light flux emitted by said source to the crystal and for returning to a detection assembly the luminescent light emitted by the crystal as a result, and a measurement probe past which the fluid or the moving surface moves, wherein the doped crystal is constituted by one of the crystals from the group comprising strontium fluoride doped with divalent ytterbium, SrF2:Yb2+; and calcium fluoride doped with divalent ytterbium, CaF2:Yb2+. In a preferred embodiment for measuring the temperatures of moving surfaces, the measurement probe includes a fiber for transmitting the light flux emitted by the light source plus at least one receiver fiber for returning the light emission given off by the doped crystal which is presented in the form of a crystal covering covering a determined location on the surface to be scanned, each of said fibers being surrounded by a metal capillary.

The present invention relates to an optical element coated with a dense uniform fluoride film, further to a method of manufacturing such coated elements. The coating is a coating that co-evaporates to form a coating of L-H coating with a high ("H") refractive index fluoride material and a low ( "L") refractive index material (a coating of L and H materials co-deposited). Lanthanides (e.g., neodymium, lanthanum, dysprosium, yttrium and gadolinium, and combinations thereof) are preferred metal fluorides used as high refractive index materials, especially preferably lanthanum fluoride (LaF 3 and gadolinium fluoride (GdF 3 )。 Aluminium fluoride (AlF 3 and alkaline earth metal fluoride (calcium, magnesium, barium and strontium fluoride) is preferred low refractive index material, magnesium fluoride (MgF 2 ) is preferred alkaline earth metal fluoride.

The invention discloses a composition of an oversized model area fluorphosphate optical fiber and a preparation method thereof. The composition of the oversized model area fluorphosphate optical fiber mainly comprises an optical fiber core part and an optical fiber cladding part. The formula comprises aluminium metaphosphate, calcium metaphosphate, lithium fluoride, barium fluoride, magnesium fluoride, strontium fluoride, zirconium fluoride, lanthanum fluoride, yttrium fluoride and rare earth oxides. The composition has the structure of gain guidance-refractive index anti-guidance, the diameter of the fibre core of the gain guidance-refractive index anti-guidance optical fiber is far more than the diameter (4-10 mu m) of the fibre core of the common monomode optical fiber, and the mode field area can be above ten thousands square microns. The core diameter is 100-500 mu m; the cladding is composed of multicomponent glass, and the cladding diameter is about 250-650 mu m; and the difference delta n between the fiber core and the cladding is less than 0.05-0.28% and solves the problem that the mode field diameter is more than 100 mu m and the problem of monomode transmission characteristics.

The invention relates to a neodymium-doped strontium fluoride laser transparent ceramic. According to the invention, neodymium ions and a strontium fluoride matrix undergo a chemical reaction to form a displacement solid solution, and hot-pressing sintering, post-treatment and other operations are carried out so as to obtain the laser transparent ceramic with a density approximate to 99.8%. A preparation method for the laser transparent ceramic comprises the following steps: preparing Nd<3+>: SrF2 nanometer powder by using an azeotropic distillation process and then carrying out azeotropic distillation with n-butanol as an entrainer to maximally remove moisture in gel, wherein obtained powder is not prone to agglomeration, has uniform particle size distribution, and has a grain size of 15 to 30 nm; and preparing the laser transparent ceramic by using vacuum hot-pressing sintering technology with LiF as a sintering aid. The prepared laser transparent ceramic has maximum transmittance of 85.83% in visible and near-infrared wave bands and has strong absorption peaks at 576 nm, 735 nm and 796 nm. The preparation method is simple, suitable for large-scale production and low in cost; and the prepared laser transparent ceramic has good optical homogeneity.