LiNbO3晶体Zui重要的缺点之一是易受光折变损伤(通常在蓝光或绿光的连续波照射下,光诱导的折射率变化)。消除这种影响的通常方法是将LN晶体保持在高温(400K或更高)下。防止光折变损伤的另一种方法是掺入MgO(对于同成分LN,通常为5mol%左右)。结果表明,掺MgO的同成分LiNbO3晶体的矫顽场值远低于未掺MgO的LN晶体,其光折变损伤阈值高于掺5mol%MgO的同成分LN晶体。
MgO:LiNbO3一种非线性晶体优化LiNbO3的性能纯LiNbO3(LN)是一种很好的光器件候选材料,但由于其低阈值的光损伤特性,有着很大的缺点。掺MgO的LN(同余组分)是解决这一问题的可能途径之一。MgO掺杂在LN中起着重要作用,其阈值激光强度提高了100倍。有趣的一点是,掺杂MgO的LN的每一个物理性质(如转变温度、活化能、光带、光吸收光谱、OH-振动频率的移动、密度和电活化能,基于我们先前的测量4)在MgO浓度略高于5%摩尔时都具有阈值组成。
特点
同质性高
透明范围广
损伤阈值高
良好的光电性能
良好的光电弹性
应用
SHG
利用光接触Nd:YVO4/PPMgOLN的紧凑型532nm微芯片激光器阵列
波导调制器
作为Nd:YAG激光器的Q开关
在室温下用于1064nm激光的倍频
电光调制器
测距仪
激光雷达
移动电话
铌酸锂25°C2.401792.326312.236222.203512.1571450°C2.403432.328072.237652.204582.1575775°C2.407222.33082.23942.206072.15884掺镁铌酸锂25°C2.384822.312482.22532.193232.1475750°C2.387782.314412.226442.194242.1486175°C2.391522.317182.228192.195672.14966
01466±2
0.81479±20.30421486±10.3013.31485±10.3034.61480±2
Congruent LN
014110.316>51486
全等LN晶体“0”透射率范围:0.32–5μmλ[µm]none0.43582.38632.28020.49162.34032.24160.54612.31142.21720.5772.29882.20680.5792.2982.20620.63282.28162.19220.69432.26782.18050.842.2462.16221.06422.22722.1463λ[µm]noneλ[µm]none0.40472.42472.31110.5792.29822.20560.40782.42022.30730.58932.29452.20270.43582.38632.27950.62342.2842.19380.48612.34412.24440.65632.27562.18670.49162.34042.24120.69072.26812.18020.49622.33762.23890.69432.26692.17930.54612.31122.21671.0642.22372.1456相互作用波长[μm]Φexp [deg]NoteSHG,o+o ⇒ e
1.0642⇒0.532174.55mol%MgO, 全LN765mol% MgO76.55mol% MgO,Li/Nb=0.9782.37mol%MgO1.0795⇒0.5397575.15mol%MgO, 全LN1.0796⇒0.5398745mol%MgO, Li/Nb=0.971.3414⇒0.6707545mol%MgO, 全LN相互作用波长[μm]T[℃]注意SHG,o+o ⇒ e
1.047⇒0.523575.3
1.0642⇒0.532125.40.6mol%MgO, 全LN78.57mol%MgO, 沿X85–109>5mol% MgO1075mol%MgO1105mol% MgO110.65mol% MgO110.87mol%MgO1.0795⇒0.539751155mol%MgO, 全LNλ[μm] τp[ns]Ithr[GW/cm2]Note0.5321CW>0.0021mol% MgO, Li/Nb=1.38
>0.0022mol% MgO, Li/Nb=1.0
0.0025mol% MgO, congruent LN
>0.0061.8mol% MgO, Li/Nb=0.96–0.99≈200.345mol%MgO0.7780.002>107mol% MgO0.780.00015>15
0.78–0.840.0001>1301kHz, 7mol%MgO1.064225>0.0250.6mol%MgO,全LN≈200.615mol% MgO20>0.03910Hz, 5mol%MgO0.04>0.80.6mol%MgO,全LN0.03>0.145Hz, 5mol% MgO1.560.00008>1.361kHz,5mol% MgO|d31(0.852µm)|=4.9pm/V|d33(0.852µm)|=28.4pm/V|d31(1.064µm)|=4.4pm/V|d33(1.064µm)|=25.0pm/V|d31(1.313µm)|=3.4pm/V|d33(1.313µm)|=20.3pm/V
LiNbO3和LiNbO3的吸收光谱:MgO(7 mol。%)晶体在吸收边缘区域
未掺杂和掺杂MgO的LN晶体的透射光谱
具有I型相匹配(oo-e)的LiNbO3:MgO(7 mol。%)晶体中SHG强度的角度依赖性
MgO:LiNbO3的寻常波和非寻常波在25°C时的热光常数