Mitsubishi Materials Corporation

Ryuichi Komatsu

Tamotsu Sugawara

Hiroyuki Shiraishi

Masakuni Takahashi

Yasuhiro Hanaue

Makio Yamashita

Genta Masada

Noriko Watanabe

Kenichi Shimosaka

Valentin Petrov

Tsuyoshi Kajitani

Etsuro Asakura

Yasuhiro Ono

A cement clinker which necessitates no considerable change in the main chemical components and mineral components of cement, is free from preheater coating problems and adverse influences on cement properties, and is effective in reducing the heat quantity required for burning; and a process for producing the cement clinker. In the process for cement clinker production a substance having a melting point higher than the temperature of a liquid phase of the cement clinker and serving as crystal nuclei for CS is incorporated include a fine powder of refractory brick, particles of an ordinary Portland cement clinker, a fine powder of a high-early-strength Portland cement clinker, a high-early-strength Portland cement, and a fine powder of quicklime. Due to this, alite generation is accelerated even at a low temperature. As a result, high-quality clinker can be produced through burning using a small unit heat quantity and no decrease in cement quality results. The process contributes to a reduction in preheater coating amount and prolongation of the life of the refractory bricks.

Cement clinker and process for producing the same

A laser apparatus includes a wavelength conversion device composed of single crystal lithium tetraborate for converting a wavelength by passing an incident laser beam therethrough. The relationship between the orientation of the crystal axis of the single-crystal lithium tetraborate and the direction of incidence of the laser beam is determined so as to prevent beam walk-off from occurring in the laser beam propagating through the conversion device. A method of converting a wavelength by passing an incident laser beam through a wavelength conversion device composed of single-crystal lithium tetraborate is also disclosed.

Wavelength conversion device composed of single-crystal lithium tetraborate, laser apparatus provided with the same and method of converting wavelength using the same

A borate single crystal which can stably perform light wavelength conversion with high efficiency down to the ultraviolet region is represented by the chemical formula (A O).(B O ) , and is an orthorhombic crystal belonging to the P2   space group, wherein A includes two elements selected from the group consisting of Li, Na, K, Rb, and Cs, and 1.5<x<2.5.

Borate crystal, growth method of the same and laser equipment using the same

Single-crystal lithium tetraborate (single-crystal Li.sub.2 B.sub.4 O.sub.7 or single-crystal LBO) as an optical converter device which stably operates for a long term, has a long life, and is compact, light and inexpensive, an optical converter device using the single crystal LBO, especially, for emitting light having a wavelength of 500 nm or less, and an optical apparatus using the optical converter device. Coherent light irradiates the light incident face of the single-crystal LBO at a predetermined incident angle, which single-crystal LBO is cut at a predetermined plane to the optical axis in order to satisfy a predetermined phase matching angle, and light having a half wavelength of the incident light is emitted. Preferably, the single-crystal LBO has a refractive index variation of 10.sup.-5 /mm or less and/or a etch-pit density of approximately 1.times.10.sup.3 /cm.sup.2. A first coherent light beam having a first wavelength and a second coherent light beam having a wavelength one-half or one-fourth of the wavelength of the first coherent light beam irradiates the incident face of the single-crystal LBO at a predetermined angle, and at least a coherent light having a wavelength one-third or one-fifth of the wavelength of the first coherent light beam is emitted by sum frequency generation, for example, when light having a wavelength of 209 nm is emitted, the wavelength of the first coherent light is 981 nm and that of the second coherent light is 266 nm.

Single-crystal lithium tetraborate and method making the same, optical

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Ube, Japan

Ryuichi Komatsu