32 results about "Yttrium orthovanadate" patented technology

An optical waveguide device 1 includes a thin layer 3 and a ridge portion 5 loaded on the thin layer 3. The thin layer 3 is made of an optical material selected from the group consisting of lithium niobate, lithium tantalate, lithium niobate-lithium tantalate, yttrium aluminum garnet, yttrium vanadate, gadolinium vanadate, potassium gadolinium tungstate; and potassium yttrium tungstate. The ridge portion 5 is made of tantalum pentoxide and has a trapezoid shape viewed in a cross section perpendicular to a direction of propagation of light. The ridge portion is not peeled off from the thin layer in a tape peeling test.

A fluorescent lamp includes a glass envelope that is light transmitting. There is means for providing a discharge inside the envelope. A discharge-sustaining fill of mercury and an inert gas is sealed inside the envelope. An underlying phosphor-containing layer is disposed inside the envelope. The underlying layer includes yttrium vanadate phosphor. A protective phosphor-containing layer is disposed over the underlying layer at a location that is more distal from the glass than the underlying layer.

A method for synthesizing yttrium orthovanadate and its derivatives is the low-temperature self-assembly solid-phase synthesis of yttrium orthovanadate and its derivatives in the presence of a template, including mixing and grinding, drying and loading, pre-sintering and grinding. sampling, burning and washing and drying steps. The method has the advantages of low cost, low energy consumption, low requirements for production equipment configuration, and the like.

The invention discloses a preparation method of a porous nano material yttrium vanadate. The preparation method comprises the following steps: firstly, preparing nano carbon spheres; then covering surfaces of the nano carbon spheres with a layer of a yttrium vanadate nano material by applying a citric acid complexing method by taking the nano carbon spheres as a template; and calcining the carbon spheres to generate CO2 gas which breaks through yttrium vanadate covering the surfaces of the carbon spheres to form gas holes on the surface of yttrium vanadate so as to generate the porous nano material yttrium vanadate. The porous nano material YVO4 disclosed by the invention has a relatively large specific area which can reach 14.37m<2> / g and is nearly four times greater than that of YVO4 not doped with carbon spheres, and the relatively large specific area can improve the reaction rate and efficiency of a pholocatalyst.

In the optical device used for metal surface polishing provided by the present invention, the laser beam emitted by the femtosecond laser source is focused on the three-dimensional moving laser beam through the yttrium vanadate birefringent crystal, the attenuation plate and the focusing objective lens in sequence. The metal surface on the platform, and the metal surface is laser polished to obtain a smooth polished surface. The optical device for metal surface polishing provided by the present invention realizes the polishing of the metal surface by controlling the relevant femtosecond laser processing parameters. Polishing, compared with the existing mechanical polishing methods, it can achieve a large area of ​​rapid polishing and micro-area polishing, without the need for auxiliary materials such as sandpaper, abrasive paste, chemical etchant; and the whole process is simple and easy to operate, and the thermal effect is negligible, can be Realize high-precision polishing; at the same time, due to the use of non-contact processing, it can effectively avoid stress damage and contamination on the surface of metal tungsten samples.

The invention relates to a method for preparing submicron concentric rings on a silicon surface with a femtosecond laser, belonging to the field of laser applications. In the present invention, a femtosecond laser single pulse is vertically incident through a yttrium vanadate crystal with a certain thickness to obtain a femtosecond laser double pulse sequence with a certain pulse delay whose polarization directions are perpendicular to each other and pulse energy is equal. The thickness of the yttrium vanadate crystal is The range of the femtosecond laser pulse should be satisfied, so that the delay range of the double pulse pulse generated after the femtosecond laser single pulse of the corresponding wavelength is about 0.5ps‑1.5ps; then use the attenuation sheet to adjust the total energy density of the femtosecond laser double pulse to the sample to be processed 1.6 to 2.2 times the ablation threshold of the material silicon; then this vertically polarized femtosecond laser double pulse is vertically focused on the surface of the material to be processed through a plano-convex lens; the number of pulse sequences focused on the surface of the material is controlled by the opening time of the optical switch For 4‑6 pieces, a single point of irradiation on the surface of the silicon material can prepare a submicron concentric ring structure on the silicon surface.