Fluoroberyllium borate non-linear optical crystals, their growth methods and uses

Abstract

A fluoroberyllium borate non-linear optical single crystal is represented by a molecular formula of MBe 2 BO 3 F 2 , 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° C., keeping at this temperature and then cooling it to the temperature of 2-10° 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.

1 - 8 . (canceled) 
     
     
         9 . A non-linear optical device comprising a fluoroberyllium borate non-linear optical crystal, having a molecular formula of MBe 2 BO 3 F 2 , wherein:
 M is selected from the group consisting of Rb and Cs,   the crystal belongs to a rhombohedral system and an R32 space group, and the crystal enables achievement of at least one of second harmonic, third harmonic, fourth harmonic, fifth harmonic or sixth harmonic generations of lasers whose wavelength is 1.064 μm.   
     
     
         10 . A non-linear optical device comprising a fluoroberyllium borate non-linear optical crystal, having a molecular formula of MBe 2 BO 3 F 2 , wherein:
 M is selected from the group consisting of Rb and Cs,   the crystal belongs to a rhombohedral system and an R32 space group, the crystal enables achievement of at least one of second harmonic, third harmonic, fourth harmonic, fifth harmonic or sixth harmonic generations of lasers, wherein the wavelengths of generated lasers are less than 200 nm.   
     
     
         11 . The non-linear optical device according to  claim 9 , wherein the device is selected from the group consisting of electrooptical devices, pyroelectric devices, harmonic generators, optical parametric oscillators, optical parametric amplifiers and optical waveguide devices for the UV region. 
     
     
         12 . The non-linear optical device according to  claim 9 , wherein the device is selected from the group consisting of optical parametric oscillators and optical parametric amplifiers for from the IR to the UV region. 
     
     
         13 . The non-linear optical device according to  claim 9 , wherein the fluoroberyllium borate non-linear optical crystal is selected from the group consisting of a rubidium fluoroberyllium borate crystal having a molecular formula of RbBe 2 BO 3 F 2  and a cesium fluoroberyllium borate, having a molecular formula of CsBe 2 BO 3 F 2 . 
     
     
         14 . The non-linear optical device according to  claim 10 , wherein the device is selected from the group consisting of electrooptical devices, pyroelectric devices, harmonic generators, optical parametric oscillators, optical parametric amplifiers and optical waveguide devices for the UV region. 
     
     
         15 . The non-linear optical device according to  claim 10 , wherein the device is selected from the group consisting of optical parametric oscillators and optical parametric amplifiers for from the IR to the UV region. 
     
     
         16 . The non-linear optical device according to  claim 10 , wherein the fluoroberyllium borate non-linear optical crystal is selected from the group consisting of a rubidium fluoroberyllium borate crystal having a molecular formula of RbBe 2 BO 3 F 2  and a cesium fluoroberyllium borate, having a molecular formula of CsBe 2 BO 3 F 2 .