LBO晶体是一种优良的倍频晶体,是目前应用比较广泛的一种倍频器件,其晶体内部光学均匀性良好、透过波段比较宽,比具有较高的匹配效率和激光损伤阈值。
应用:激光倍频等。
LBO晶体的主要优点:
•可透光波段范围宽(160—2600nm)
•光学均匀性好,内部包络少
•倍频转换效率较高(相当于KDP晶体的3倍)
•高损伤域值(1.3ns脉宽的1053nm激光可达10GW/cm2)
•接收角度宽,离散角度小
• I,II类非临界相位匹配(NCPM)的波段范围宽
•光谱非临界相位匹配(NCPM)接近1300nm
LBO晶体的主要应用:
. 二倍频方面:
1. 医用与工业用途的Nd:YAG激光
2. 科研与军事用途的高功率Nd:YAG与Nd:YLF激光
3. Nd:YVO4,Nd:YAG和Nd:YLF激光的泵浦
4. 红宝石,Ti:Sappire与Cr:LiSAF激光
. 三倍频方面:
1. Nd:YAG与Nd:YLF激光
2. 光学参量放大器(OPA)与光学参量振荡器(OPO)
3. 高功率1340nm的Nd:YAP激光的二,三倍频
基本性质
晶体结构 |
Orthorhombic, Space group Pna21, Point group mm2 |
晶格参数 |
a = 8.4473Å, a = 7.3788Å, c = 5.139Å, z = 2 |
熔点 |
About 834°C |
莫氏(Mohs)硬度 |
6 |
密度 |
2.47 g/cm3 |
热膨胀系数 |
ax=10.8x10-5/k ay=-8.8x10-5/k az=3.4x10-5/k |
吸收系数 |
<0.1%/cm at 1064nm |
光学性质
Transparency Range |
160-2600nm |
SHG Phase Matchable Range |
551-2600nm(Type I) 790-2150(Type II) |
Therm-Optic Coefficient(°C, λ in μ m)
|
dnx/dT=-9.3X10-6
dny/dT=-13.6X10-6
dnz/dT=(-6.3-2.1 λ)X10-6 |
Absorption Coefficient |
<0.1%/cm at 1064nm
<0.3%/cm at 532nm |
Angle Acceptance |
6.54mrad-cm (φ, Type I,1064 SHG)
15.27mrad-cm (q, Type II,1064 SHG) |
Temperature Acceptance |
4.7°C-cm (Type I, 1064 SHG)
7.5°C-cm (Type II,1064 SHG) |
Spectral Acceptance |
1.0nm-cm (Type I, 1064 SHG)
1.3nm-cm (Type II,1064 SHG) |
Walk-off Angle |
0.60° (Type I 1064 SHG)
0.12° (Type II 1064 SHG) |
NLO Coefficients |
deff(I)=d32cosΦ (Type I in XY plane)
deff(I)=d31cos2θ+d32sin2θ (Type I in XZ plane)
deff(II)=d31cosθ (Type II in YZ plane)
deff(II)=d31cos2θ+d32sin2θ (Type II in XZ plane) |
Non-vanished LBO susceptibilities |
d31=1.05±0.09pm/V
d32=-0.98±pm/V
d33=0.05±0.006pm/V |
Sellmeier Equations(λ in μ m) |
nx2=2.454140+0.011249/(λ2-0.011350)-0.014591λ2-6.60x10-5 λ4
ny2=2.539070+0.012711/(λ2-0.012523)-0.018540λ2=2.0x10-4 λ4
nz2=2.586179+0.013099/(λ2-0.011893)-0.017968λ2=2.26x10-4 λ4 |
参数
•波前畸变:小于λ/8 @ 633nm
•尺寸公差: (W±0.1mm)x(H±0.1mm)x(L+0.2/-0.1mm)
•通光孔径: 90% 中央直径
•50mW绿光检测无可见散射路径
•平面度:λ/8 @ 633nm
•划痕/Dig code: 10/5 to MIL-PRF-13830B
•平行度: 优于20 arc seconds
•垂直度: 5 arc minutes
•角度偏差:△θ≤0.25°,△φ≤±0.25°
•损伤阈值(GW/cm2): >10 for 1064nm, TEM00, 10ns, 10HZ (polished only)
>1 for 1064nm, TEM00, 10ns, 10HZ (AR-coated)
>0.5 for 532nm, TEM00, 10ns, 10HZ (AR-coated)
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