Chinese Academy of Sciences

Rukang Li

Chuangtian Chen

Xiaoyang Wang

Feidi Fan

Bo Xu

Yong Zhu

Lijuan Liu

Xiaohong Wen

Chengqian Zhang

Yingying Ma

A potassium fluoroboratoberyllate crystal oblique-incidence laser frequency multiplier, comprising: a flake-like potassium fluoroboratoberyllate crystal having parallel front and back polished surfaces; a front antireflection film and a back antireflection film; a columnar crystal support provided with a square holding slot and a light through-hole; and external heating jackets; the crystal is disposed in the square holding slot, the front and back surfaces of the crystal conforming to a main surface of the square holding slot, a normal of the main surface of the holding slot forming an angle &#x3b8; with the central axis of the crystal support; a laser at a fundamental frequency passes through the front antireflection film, and a frequency-multiplied laser generated in the crystal is transmitted out through the back antireflection film. The present invention has a simple structure and a low cost, and is suitable for medium- and high-power laser systems.

Potassium fluoroboratoberyllate crystal oblique-incidence laser second harmonic generator

The present invention relates to a borate birefringent crystal applicable to ultraviolet (UV) or deep ultraviolet (DUV) range, with chemical formula of BaMg(BO). The borate birefringent crystal belongs to a trigonal system, with space group of R-3 wherein a=0.70528(3) nm, c=1.65520(9) nm and Z=12. The barium magnesium borate birefringent crystal is negative uniaxial (n&#x3c;n) with a birefringence of 0.077-0.229 and a transmission range of 177-3000 nm. The crystal is easy to cut, grind, polish, and preserve, and is stable in air and is not easy to deliquesce. The barium magnesium borate birefringent crystal can be grown by the Czochralski method, flux method or the method of spontaneous crystallization from a melt, and has larger birefringence (n&#x2212;n=0.077-0.229). The crystal has important applications in the fields of optics and communications, e.g. for fabricating the polarizing beam splitter prism.

Borate birefringent crystal applicable to ultraviolet (UV) or deep ultraviolet (DUV) range, and growth method and use thereof

The present invention relates to a KBBF family nonlinear optical crystal-prism coupler and its method of fabrication. The coupler comprises: a KBBF family crystal with two smooth surfaces; transition layers each of which is deposited on respective one of the two smooth surfaces of the KBBF family crystal; and a pair of prisms each of which optically contacts with respective one of the activated transition layers. The present invention further provides a KBBF family nonlinear optical crystal-prism coupler that comprises: a KBBF family crystal with two smooth surfaces; a pair of prisms each of which has a smooth surfaces; first transition layers each of which is deposited on respective one of the two smooth surfaces of the KBBF family crystal; and second transition layers each of which is deposited on a smooth surface of respective one of the pair of prisms, wherein the first and second transition layers are integral by optical contact. The coupling between the KBBF family crystal and the prisms is achieved by optical contact through transition layers to improve bonding strength.

Optical coupling device having KBBF group crystal coupled with prisms and method for manufacturing same

A fluoroberyllium borate non-linear optical single crystal is represented by a molecular formula of MBeBOF, wherein M is Rb or Cs. The crystal can be grown by the flux method comprising the steps of mixing a fluoroberyllium borate compound and a flux in proportion, heating the mixture up to 750-800&#xb0; C., keeping at this temperature and then cooling it to the temperature of 2-10&#xb0; C. above the saturating point to obtain a fluoroberyllium borate solution at high temperature; putting the seed crystal fixed on the end of a crystal hanging bar into the fluoroberyllium borate solution at high temperature, rotating the crystal hanging bar, cooling the melt solution to its saturating point, then cooling it again slowly, pulling the obtained crystal out of the solution surface, cooling it to room temperature, then obtaining the present fluoroberyllium borate non-linear optical crystal. The crystal has nonlinear optical effect, broad transmittance wave and UV cut-off edge at 150 nm; neither deliquesces nor dissolves in dilute hydrochloric acid or dilute nitric acid; and has good chemical stability. The present crystal is applicable to the need of harmonic generations in the UV range and can be used to make nonlinear optical devices, achieve the output device for the second, third, fourth, fifth or sixth harmonic generations of Nd:YAG laser. They can be also used in harmonic generation devices of other laser wavelength and to generate coherent light with wavelength at or less than 266 nm.

Fluoroberyllium borate non-linear optical crystals and their growth and applications

The present invention provides a cesium-rubidium-borate nonlinear optical crystal, which is represented by the chemical formula CsRbBO(0&#x3c;x&#x3c;1), and belongs to the P222space group with the unit cell parameters in the following range: a=8.202-8.514 &#x212b;, b=10.075-9.140 &#x212b;, c=5.375-6.207 &#x212b; and Z=4. A preparation method of the crystal is as follows: a cesium salt, a rubidium salt and a boron-containing compound are mixed pro rata, heated, kept at a temperature, and then cooled down to obtain the cesium-rubidium-borate. The cesium-rubidium-borate and a flux are mixed and heated to form a melt to obtain a mixing melt. Then a seed crystal attached to a seed rod is dipped into the mixing melt and the seed rod is rotated simultaneously. The melt is kept at 620-780&#xb0; C., and then cooled down slowly at a rate of 0-5&#xb0; C. per day. The obtained crystal is drawn out of the melt surface and cooled down to room temperature. Thereby, the cesium-rubidium-borate nonlinear optical crystal is obtained. The crystal can be used for laser light wavelength conversion, optical parametric amplification, electrooptic modulation, optical waveguide and etc.

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Beijing, China

Rukang Li