NONLINEAR OPTICAL CRYSTAL OF BARIUM CESIUM BORATE, PREPARATION METHOD AND USE THEREOF

Abstract

A nonlinear optical crystal of barium cesium borate, a preparation method and use thereof are provided. The nonlinear optical crystal has a chemical formula of CsBa.sub.3B.sub.11O.sub.20 and a molecular weight of 983.84. The nonlinear optical crystal belongs to an orthorhombic crystal system; a space group of the nonlinear optical crystal is Cmc2.sub.1; lattice parameters of the nonlinear optical crystal are a=19.011(7) Å, b=10.837(4) Å, c=8.578(3) Å, Z=4, V=1767.4(11) Å.sup.3; and a Mohs hardness of the nonlinear optical crystal is 4-5. The nonlinear optical crystal is grown by a flux method. The nonlinear optical crystal of the barium cesium borate obtained is used for a manufacture of non-linear optical devices. The nonlinear optical crystal has a large size of centimeter-scale at least and is prepared by fast, simple and low-cost operations. The nonlinear optical crystal prepared has a large size, a wide light transmission band and good mechanical properties.

Claims

1. A nonlinear optical crystal of barium cesium borate, wherein the nonlinear optical crystal has a chemical formula of CsBa.sub.3B.sub.11O.sub.20 and a molecular weight of 983.84, the nonlinear optical crystal belongs to an orthorhombic crystal system, a space group of the nonlinear optical crystal is Cmc2.sub.1, lattice parameters of the nonlinear optical crystal are a=19.011(7) Å, b=10.837(4) Å, c=8.578(3) Å. Z=4, V=1767.4(11) Å.sup.3, and a Mohs hardness of the nonlinear optical crystal is 4-5.

2. A method for preparing the nonlinear optical crystal of the barium cesium borate according to claim 1, wherein the nonlinear optical crystal is grown using a compound flux method with specific operation steps of: a, placing and mixing a barium-containing compound selected from the group consisting of BaO, BaCO.sub.3, Ba(NO.sub.3).sub.2, BaC.sub.2O.sub.4, Ba(OH).sub.2, Ba(C.sub.2H3O.sub.2).sub.2, BaF.sub.2, and BaCl.sub.2; a cesium-containing compound selected from the croup consisting of Cs.sub.2O, Cs.sub.2CO.sub.3, CsNO.sub.3, Cs.sub.2C.sub.2O.sub.4.nH.sub.2O, CsOH, CsC.sub.2H.sub.3O.sub.2, CsF, and CsCl; and a boron-containing compound selected from the group consisting of H.sub.3BO.sub.3 and B.sub.2O.sub.3 in a mortar to obtain a first compound mixture, grinding the first compound mixture thoroughly and transferring the first compound mixture into an open corundum crucible with Φ100 mm×100 mm, pressing the first compound mixture firmly and placing the first compound mixture into a muffle furnace, raising a temperature slowly to 450° C. and holding at the temperature of 450° C. for 5 hours, discharging a gas as much as possible, taking out the open corundum crucible after cooling down, taking out the first compound mixture and re-grinding the first compound mixture evenly, then putting the first compound mixture in the open corundum crucible again, keeping the first compound mixture in the muffle furnace at a temperature of 750° C. for 48 hours before taking the first compound mixture out then mashing and grinding the first compound mixture in the mortar to obtain a barium cesium borate compound CsBa.sub.3B.sub.11O.sub.20, then conducting an X-ray analysis on the barium cesium borate compound, wherein an X-ray spectrum obtained as above is consistent with an X-ray spectrum of a finished product CsBa.sub.3B.sub.11O.sub.20 single crystal after being grinded into a powder; b, adding the barium cesium borate compound obtained in step a to a flux at a molar ratio of 1:0.5-3 to obtain a second compound mixture, heating up the second compound mixture to a temperature of 700-750° C. and holding at the temperature of 700-750° C. for 10-100 hours before cooling down to 680-618° C. to obtain a mixed melt of barium cesium borate compound and the flux, wherein the flux is PbO, PbCO.sub.3, Pb(NO.sub.3).sub.2, PbC.sub.2O.sub.4, Pb(OH).sub.2, Pb(C.sub.2H.sub.3O.sub.2).sub.2.3H.sub.2O, or Cs.sub.2O; c, crystallizing by slowly cooling down to room temperature at a rate of 0.5-5° C./h to obtain seed crystals, or using a platinum wire suspension method during a cooling process to obtain crystals as the seed crystals; then growing the seed crystals on a surface of or inside the mixed melt of the barium cesium borate compound and the flux; d, feeding the seed crystals fixed on a seed rod from a top of a crystal growth furnace to make the seed crystals contact with the surface of the mixed melt of the barium cesium borate compound and the flux or extend into the mixed melt of the barium cesium borate compound and the flux, reducing the temperature to 618-660° C., and rotating the seed rod at a speed of 0-100 rpm; e, separating a crystal from the surface of the mixed melt after the crystal grows into a required size, and cooling down to room temperature at a rate of 1-100° C./h, then taking the crystal out of the crystal growth furnace slowly to obtain the nonlinear optical crystal of the barium cesium borate.

3. A method of using the nonlinear optical crystal of the barium cesium borate according to claim 1, comprising using the nonlinear optical crystal in a manufacture of a frequency multiplication generator, a frequency up converter, a frequency down converter, or an optical parametric oscillator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is an X-ray diffraction spectrum of barium cesium borate powder according to the present invention;

[0025] FIG. 2 is a structural diagram of barium cesium borate single crystal according to the present invention;

[0026] FIG. 3 is a functional diagram of a nonlinear optical device manufactured using the cesium barium borate crystal of the present invention, in which: 1 represents a laser; 2 represents an emission light beam; 3 represents a CsBa.sub.3B.sub.11O.sub.20 crystal; 4 represents an emergent light beam; and 5 represents a filter.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention will be described in detail below with reference to the drawings and embodiments:

EXAMPLE 1

[0028] Based on the chemical formula: Ba(NO.sub.3).sub.2+H.sub.3BO.sub.3+Cs.sub.2CO.sub.3.fwdarw.CsBa.sub.3B.sub.11O.sub.20+NO.sub.2↑+CO.sub.2↑+O.sub.2↑, compound CsBa.sub.3B.sub.11O.sub.20 was synthesized using a solid-state synthesis method shown as follows.

[0029] Ba(NO.sub.3).sub.2, Cs.sub.2CO.sub.3, and H.sub.3BO.sub.3 were placed in a mortar at a molar ratio of 6:1:22, mixed and grinded thoroughly, then transferred into an open corundum crucible with Φ100 mm×100 mm.

[0030] The mixture was pressed firmly, and placed into a muffle furnace. The temperature was raised up slowly to 450° C. and held at this temperature for 5 hours. Gas was discharged as much as possible; and the crucible was taken out after cooled down. The sample was taken out, re-grinded evenly, placed in the crucible, and kept in the muffle furnace at a temperature of 750° C. for 48 hours before being taken out then mashed and grinded in a mortar to obtain cesium barium borate compound CsBa.sub.3B.sub.11O.sub.20. X-ray analysis was then conducted on the compound. The X-ray spectrum obtained as above is consistent with that of the finished product CsBa.sub.3B.sub.11O.sub.20 single crystal after grinded into powder.

[0031] The obtained compound cesium barium borate was add to flux PbO at a molar ratio of 1:3. The mixture was heated to a temperature of 700° C. and kept at such a temperature for 30 h before cooled down to 680° C. to obtain a mixed melt of cesium barium borate and the flux.

[0032] Crystallization was conducted by slowly cooling down to room temperature at a rate of 0.5° C./h to obtain seed crystals.

[0033] The seed crystal fixed on the seed rod was fed from the top of the crystal growth furnace to make the seed crystal contact with the surface of the mixed melt of cesium barium borate and the flux.

[0034] The temperature was reduced to 660° C., and the seed rod was rotated at a speed of 70 rpm.

[0035] After growing into the required size, the crystal was separated from the surface of the melt. The temperature was reduced to room temperature at a rate of 80° C./h, then the crystal was taken out of the furnace to obtain the nonlinear optical crystal of barium cesium borate in a size of 30 mm×30 mm×10 mm.

[0036] According to the method described in Example 1, the reaction formula BaO+B.sub.2O.sub.3+Cs.sub.2O+O.sub.2.fwdarw.CsBa.sub.3B.sub.11O.sub.20+Cl.sub.2↑+H.sub.2O↑ was used to synthesize compound CsBa.sub.3B.sub.11O.sub.20, and nonlinear optical crystal of cesium barium borate CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 2

[0037] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula Ba(OH).sub.2+H.sub.3BO.sub.3+CsOH.fwdarw.CsBa.sub.3B.sub.11O.sub.20+H.sub.2O↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0038] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and flux Cs.sub.2O were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:Cs.sub.2O=1:0.5, into an open platinum crucible with Φ100 mm×100 mm. The crucible was put into a crystal growth furnace, heated to 750° C., and kept at such a temperature for 20 hours before cooled down to 672° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0039] The temperature was decreased slowly at a rate of 1° C./h, and during this cooling process, a platinum wire suspension method was utilized to obtain small crystals, i.e., seed crystals.

[0040] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along the c-axis was fixed to the lower end of a seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was in contact with the liquid surface of the mixed melt. The temperature was reduced to 650° C., and the seed rod was rotated at a speed of 30 rpm.

[0041] After growing into the required size, the crystal was separated from the surface of the melt. The temperature was reduced to room temperature at a rate of 40° C./h, then the crystal was taken out of the furnace to obtain the nonlinear optical crystal of barium cesium borate CsBa.sub.3B.sub.11O.sub.20 in a size of 70 mm×70 mm×15 mm.

[0042] According to the method described in Example 2, the reaction formula Cs.sub.2CO.sub.3+B.sub.2O.sub.3+BaCO.sub.3.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑ was used to synthesize compound CsBa.sub.3B.sub.11O.sub.20, and nonlinear optical crystal of CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 3

[0043] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula BaC.sub.2O.sub.4+H.sub.3BO.sub.3+Cs.sub.2C.sub.2O.sub.4.nH.sub.2O+O.sub.2.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑+H.sub.2O↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0044] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and the flux CsOH were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:CsOH=1:1.5, into an open platinum crucible with Φ80 mm×80 mm. The crucible was put into a crystal growth furnace, heated to 740° C., and kept at such a temperature for 10 hours before cooled down to 650° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0045] Crystallization was conducted by slowly cooling down to room temperature at a rate of 2.5° C./h to obtain seed crystals.

[0046] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along any axis was fixed to the lower end of the seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was in contact with the liquid surface of the mixed melt. The temperature was reduced to 630° C., and the seed rod was rotated at a speed of 90 rpm.

[0047] After growing into the required size, the crystal was lifted away from the surface of the melt. The temperature was reduced to room temperature at a rate of 100° C./h, then the crystal was taken out of the furnace slowly to obtain the nonlinear optical crystal of barium cesium borate in a size of Φ32 mm×32 mm×25 mm.

[0048] According to the method described in Example 3, the reaction formula BaO+H.sub.3BO.sub.3+Cs.sub.2O.fwdarw.CsBa.sub.3B.sub.11O.sub.20+H.sub.2O↑ was used to synthesize compound CsBa.sub.3B.sub.11O.sub.20, and nonlinear optical crystal of cesium barium borate CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 4

[0049] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula Ba(OH).sub.2+H.sub.3BO.sub.3+CsOH.fwdarw.CsBa.sub.3B.sub.11O.sub.20+H.sub.2O↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0050] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and the flux Cs.sub.2CO.sub.3 were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:Cs.sub.2CO.sub.3=1:2.6, into an open platinum crucible with Φ100 mm×100 mm. The crucible was put into a crystal growth furnace, heated to 720° C. and kept at such a temperature for 40 hours before cooled down to 640° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0051] Crystallization was conducted by slowly cooling down to room temperature at a rate of 3° C./h to obtain seed crystals.

[0052] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along any axis was fixed to the lower end of the seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was immersed in the mixed melt. The temperature was reduced to 618° C., and the seed rod was not rotated at a speed of 0 rpm.

[0053] After growing into the required size, the crystal was separated from the surface of the melt. The temperature was reduced to room temperature at a rate of 60° C./h, then the crystal was taken out of the furnace slowly to obtain the nonlinear optical crystal of barium cesium borate CsBa.sub.3B.sub.11O.sub.20 in a size of Φ37 mm×37 mm×15 mm.

[0054] According to the method described in Example 4, the reaction formula Ba(NO.sub.3).sub.2+B.sub.2O.sub.3+CsNO.sub.3.fwdarw.CsBa.sub.3B.sub.11O.sub.20+NO.sub.2↑+O.sub.2↑ was used to synthesize compound CsBa.sub.3B.sub.11O.sub.20, and nonlinear optical crystal of cesium barium borate CsBa.sub.3B.sub.11O.sub.20 can also be obtained.

EXAMPLE 5

[0055] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula BaCO.sub.3+B.sub.2O.sub.3+Cs.sub.2O.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0056] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and the flux Cs.sub.2CO.sub.3 were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:Cs.sub.2CO.sub.3=1:2, into an open platinum crucible with Φ100 mm×100 mm. The crucible was put into a crystal growth furnace, heated to 735° C., and kept at such a temperature for 60 hours before cooled down to 655° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0057] The temperature was decreased slowly at a rate of 4° C./h, and during this cooling process, a platinum wire suspension method was utilized to obtain small crystals, i.e., seed crystals.

[0058] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along any axis was fixed to the lower end of the seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was immersed in the mixed melt. The temperature was reduced to 625° C., and the seed rod was rotated at a speed of 55 rpm.

[0059] After growing into the required size, the crystal was separated from the surface of melt. The temperature was reduced to room temperature at a rate of 70° C./h, then the crystal was taken out of the furnace slowly to obtain the nonlinear optical crystal of barium cesium borate CsBa.sub.3B.sub.11O.sub.20 in a size of 17 mm×17 mm×18 mm.

[0060] According to the method described in Example 5, the reaction formula BaC.sub.2O.sub.4+H.sub.3BO.sub.3+Cs.sub.2C.sub.2O.sub.4.nH.sub.2O+O.sub.2.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑+H.sub.2O↑ was used to synthesize CsBa.sub.3B.sub.11O.sub.20 compound, and nonlinear optical crystal of cesium barium borate CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 6

[0061] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula BaCl.sub.2+B.sub.2O.sub.3+CsOH+O.sub.2.fwdarw.CsBa.sub.3B.sub.11O.sub.20+Cl.sub.2↑+H.sub.2O↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0062] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and the flux Pb(OH).sub.2 were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:Pb(OH).sub.2=1:2.5, into an open platinum crucible with Φ100 mm×100 mm, heated to 710° C., and kept at such a temperature for 100 hours before cooled down to 645° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0063] Crystallization was conducted by slowly cooling down to room temperature at a rate of 5° C./h to obtain seed crystals.

[0064] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along the c-axis was fixed to the lower end of the seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was immersed in the mixed melt. The temperature was reduced to 632° C., and the seed rod was rotated at a speed of 60 rpm.

[0065] After the growth was completed, the crystal was separated from the surface of melt. The temperature was reduced to room temperature at a rate of 20° C./h, then the transparent nonlinear optical crystal of barium cesium borate CsBa.sub.3B.sub.11O.sub.20 in a size of 50 mm×70 mm×15 mm was obtained.

[0066] According to the method described in Example 6, the reaction formula BaC.sub.2O.sub.4+H.sub.3BO.sub.3+Cs.sub.2C.sub.2O.sub.4.nH.sub.2O+O.sub.2.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑+H.sub.2O↑ was used to synthesize CsBa.sub.3B.sub.11O.sub.20 compound, and nonlinear optical crystal of CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 7

[0067] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula BaCO.sub.3+B.sub.2O.sub.3+Cs.sub.2O.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0068] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and the flux PbO were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:PbO=1:2.8, into an open platinum crucible with Φ100 mm×100 mm, heated to 700° C., and kept at such a temperature for 70 hours before cooled down to 670° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0069] The temperature was decreased slowly at a rate of 1.5° C./h, and during this cooling process, a platinum wire suspension method was utilized to obtain small crystals, i.e., seed crystals.

[0070] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along any axis was fixed to the lower end of the seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was in contact with the liquid surface of the mixed melt. The temperature was reduced to 635° C., and the seed rod was rotated at a speed of 85 rpm.

[0071] After growth was completed, the crystal was separated from the surface of melt. The temperature was reduced to room temperature at a rate of 10° C./h, then the transparent nonlinear optical crystal of barium cesium borate CsBa.sub.3B.sub.11O.sub.20 in a size of 50 mm×50 mm×14 mm was obtained.

[0072] According to the method described in Example 7, the reaction formula BaO+B.sub.2O.sub.3+Cs.sub.2O.fwdarw.CsBa.sub.3B.sub.11O.sub.20+H.sub.2O↑ was used to synthesize CsBa.sub.3B.sub.11O.sub.20 compound, and nonlinear optical crystal of CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 8

[0073] Compound CsBa.sub.3B.sub.11O.sub.20 was synthesized based on the reaction formula Ba(NO.sub.3).sub.2+B.sub.2O.sub.3+CsNO.sub.3.fwdarw.CsBa.sub.3B.sub.11O.sub.20+NO.sub.2↑+O.sub.2↑, wherein the molar ratio of each compound was in accordance with the molecular formula, and the detailed operation steps were carried out according to Example 1.

[0074] The synthesized compound CsBa.sub.3B.sub.11O.sub.20 and the flux PbF.sub.2 were placed, at a molar ratio of CsBa.sub.3B.sub.11O.sub.20:PbF.sub.2=1:3, into an open platinum crucible with Φ150 mm×150 mm, heated to 715° C., and kept at such a temperature for 50 hours before cooled down to 630° C. As a result, a mixed melt of barium cesium borate and the flux was obtained.

[0075] Crystallization was conducted by slowly cooling down to room temperature at a rate of 3.5° C./h to obtain seed crystals.

[0076] The CsBa.sub.3B.sub.11O.sub.20 seed crystal cut along any axis was fixed to the lower end of the seed rod with platinum wire, and introduced into the crucible through the small hole on the top of the furnace, so that the seed crystal was in contact with the liquid surface of the mixed melt. The temperature was reduced to 620° C., and the seed rod was rotated at a speed of 100 rpm.

[0077] After growth was completed, the crystal was separated from the surface of melt. The temperature was reduced to room temperature at a rate of 1° C./h, then the transparent nonlinear optical crystal of barium cesium borate CsBa.sub.3B.sub.11O.sub.20 in a size of 70 mm×70 mm×20 mm was obtained.

[0078] According to the method described in Example 8, the reaction formula Ba(CH.sub.3COO).sub.2+B.sub.2O.sub.3+Cs.sub.2CO.sub.3+O.sub.2.fwdarw.CsBa.sub.3B.sub.11O.sub.20+CO.sub.2↑+H.sub.2O↑ was used to synthesize CsBa.sub.3B.sub.11O.sub.20 compound, and nonlinear optical crystal of CsBa.sub.3B.sub.11O.sub.20 was also obtained.

EXAMPLE 9

[0079] Any one of the nonlinear optical crystals of CsBa.sub.3B.sub.11O.sub.20 obtained in Examples 1-8 was processed in a matching direction to manufacture a frequency multiplier device with a size of 4 mm×4 mm×8 mm, and placed in position 3 as shown in FIG. 3. At room temperature, a Q-switched Nd:YAG laser was used as the light source; and the incident wavelength was 1064 nm. An infrared light beam 2 with a wavelength of 1064 nm was emitted from the Q-switched Nd:YAG laser 1 and entered the CsBa.sub.3B.sub.11O.sub.20 crystal 3 to generate a green frequency doubled light with a wavelength of 532 nm, and the emergent light beam 4 contained the infrared light with a wavelength of 1064 nm and the green light with a wavelength of 532 nm. Through the filter 5, the infrared light component was removed and a green laser with a wavelength of 532 nm was obtained.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and should be covered within the scope of the claims of the present invention.