中红外高能量输出复合腔抽运光参量振荡器

报道了采用复合腔技术研究Nd:YAG激光抽运LiNbO₃晶体光参量振荡器(OPO)的实验研究结果。得到OPO输出单脉冲平均能量56.4mJ,闲频光(3097nm)脉冲平均能量22.8mJ,脉宽8ns,抽运光转换成参量光输出效率46%(重频1Hz～10Hz)。测得角度调谐的波长范围是:信频光1479nm～1621nm,闲频光3097nm～3793nm。     

基于矢量和的微波光子移相器研究

基于矢量和（vectorsum）原理,利用50：50光纤耦合器、可变光延时线（VDL）、可变光衰减器（VOA）构建了微波光子移相器。以宽带光为载波有效地解决了合波处光波相位不同引起的微波信号不稳定的问题;利用马赫-曾德（M—Z）LiNbO3调制器在不同工作电压下的反相调制特性,设定调制器的不同偏置电压,同时配合调节两支...     

周期极化掺镁铌酸锂晶体的光学参量振荡

采用短脉冲极化电场法,在1 mm厚的掺摩尔分数0.05镁的铌酸锂晶体上成功制备了周期为30μm的极化光栅。以输出波长为1.064μm的声光调QNd∶YAG固体激光器作为基频抽运源对其进行了光学参量振荡实验,光参量振荡阈值功率为45 mW(重复频率为1 kHz),在输入功率为490 mW,控温炉温度为160℃时,获得了94 mW的波长为1544 nm的信号光输出,转换效率达到19.2%。并且通过调谐晶体温度(20~180℃),获得了调谐范围为1503~1550 nm的信号光稳定输出。实现了可调谐红外光的稳定输出,验证了晶体周期结构的均匀性。     

Single-drive LiNbO/sub 3/ Mach-Zehnder modulator with widely DC tunable chirp

We present a 10-Gb/s LiNbO/sub 3/ Mach-Zehnder modulator that allows tuning of the chirp in a wide range (-0.7/spl divide/0.7) by applying just a dc voltage, while the radio-frequency section is single drive. The device shows uniform performances across the chirp tuning range. By tuning chirp value, transmission tests showed power penalty less than 2 dB for spans up to 2100 ps/nm.     

MgO∶LiNbO_3晶体中超短中红外非共线相位匹配光参量放大过程角度的优化选择

计算了MgO∶LiNbO3中超短中红外光参量放大(OPA)过程中晶体的相位匹配角与非共线角的优化选择。结果表明,对于800nm波长的抽运光,信号光波长为1053nm时,非共线角α优化在1.74°~2°之间;当信号光波长在1046~1067nm内变化时,α在1.05°~2.18°之间,并且当信号光波长为1057nm,α=1.76°时,可实现三波间群速度的完全匹配。同时还得到了抽运光中心波长在780~810nm之间变化时,实现完全群速度匹配时的注入信号光波长与对应的中红外光以及相应的非共线角与相位匹配角。     

铌酸锂用于灯泵Cr-Tm:YAG激光器的调Q与调谐

为了简化激光器结构,减少腔内损耗,首次提出利用LiNbO3电光晶体较高的色散特性,实现2μm波段可调谐激光器的调Q与调谐。将LiNbO3晶体加工成单块特殊形状的棱镜,作为主动调Q器件,用于2μm波段灯泵Cr-Tm：YAG激光器,以产生巨脉冲,该棱镜还同时具有调谐的功能。将该棱镜插入室温灯泵的Cr-Tm：YAG激光器中,实现了1．95～2.08μm范围的调Q、调谐运转,重复频率为1-5Hz。实验结果表明,所提出的方法可行。     

Photochemical vapour deposition of phosphorus nitride using an ArF excimer laser

The photochemical deposition of phosphorus nitride film on InP substrates using an ArF excimer laser (wavelength = 193 nm) to decompose a mixture of PH3-NH3 gases and synthesise the film is presented. The deposition temperature can be reduced from 480°C used in the thermal-CVD technique to 300°C. The film deposited photochemically exhibits a much larger resistivity and lower leakage current than that obtained by the thermal-CVD technique at 300°C. The minimum interface state density measured by C/V curves is 1012 eV?l cm?2 at (Ec ? 0.3) eV.     

近化学计量比掺镁铌酸锂晶体周期极化特性研究

采用汽相输运平衡技术制备出了高质量近化学计量比掺镁铌酸锂晶体 ,系统研究了晶体中的 [Li]/ [Nb]比含量对其畴极化电场的影响 .实验结果表明 :随着晶体中 [Li]/ [Nb]比的提高 ,畴极化反转电场呈明显下降趋势 ,使用近化学计量比掺镁铌酸锂晶体 ,我们在 3.5± 0 .1kV/mm大小的外加极化电场条件下 ,成功地实现了 1.0mm厚度的周期极化畴反转 .我们用铌酸锂晶体的缺陷模型对实验结果给出了合理的解释 .     

Further comments on t.i.r. deflector/modulator performance

T.I.R. modulator/deflector far-field order intensities are shown to agree with prediction for LiNbO3 xy-cut devices, and a `blazing? effect, controlled by crystal orientation, is suggested. Zero-order extinction ratios were between 40:1 and 140:1, and seemed optical-finish limited. Misalignment of a 0.1 mm pitch interdigitated electrode device by ±5° halved the device sensitivity, indicating the possibility of use with uncollimated light. White-light (incoherent) operation and optimisation prospects are reported.     

Integrated optical, acoustically tunable wavelength filter

A TM/TE convertor is combined with a TE-pass polariser on a common LiNbO/sub 3/ chip to obtain an integrated optical, acoustically tunable wavelength filter. Its tuning range is 1.45-1.57 mu m wavelength with a filter half-width of 2.8 nm. Due to the combined acoustical/optical strip guide structure used in the mode convertor, a very low acoustic drive power of only 9 mW is required.<>     

Radiation conductance of SSBW IDT on rotated Y-cuts of LiNbO3

The letter deals with radiation conductance of an interdigital transducer (IDT) for surface skimming bulk waves (SSBWs) on 41°- and 64°-rotated Y-cuts of LiNbO3. The radiation conductance was estimated theoretically by two methods and was compared with experimental results. The frequency response of SSBW IDTs on these cuts of LiNbO3 is similar to that of a conventional surface acoustic wave transducer, but markedly different from the response obtained when launching SSBWs from an IDT on rotated Y-cuts of quartz.     

压电晶体切向对声表面波陀螺刻度因子的影响

刻度因子是陀螺的重要指标,而压电晶体切向对声表面波(SAW)陀螺刻度因子有重要影响。首先以铌酸锂作为分析声波波传特性的基板材料,建立不同的波传角度和不同的切面与各种模态SAW波速的物理数学模型,接着探讨旋转扰动时二次旋转欧拉角与X切、Y切及Z切等铌酸锂晶体中的陀螺效应,分析不同切向刻度因子的变化规律。根据计算结果,铌酸锂晶体中X切Y传(XY)、128°Y切X传(128°YX)、30°ZX、ZX和150°ZX对应的声表面波陀螺刻度因子最大,同时也得出了适合应用于声表面波陀螺的相对敏感切向为声表面波波速接近于慢横波时对应的切向。     

Silicon Resonator Based 3.2 $mu$W Real Time Clock With $pm$10 ppm Frequency Accuracy

This paper presents an ultra-low power generic compensation scheme that is used to implement a real time clock based on an AlN-driven 1 MHz uncompensated silicon resonator achieving 3.2 ?W power dissipation at 1 V and ±10 ppm frequency accuracy over a 0-50°C temperature range. It relies on the combination of fractional division and frequency interpolation for coarse and fine tuning respectively. By proper calibration and application of temperature dependent corrections, any frequency below that of the uncompensated resonator can be generated yielding programmability, resonator fabrication tolerances and temperature drift compensation without requiring a PLL. To minimize the IC area, a dual oscillator temperature measurement concept based on a ring oscillator/resistor thermal sensor was implemented yielding a resolution of 0.04°C. The IC was fabricated on a 0.18 ?m 1P6M CMOS technology.     

Mg:Er:LiNbO3晶体的激光性能和550nm寿命特性研究

为了测试Mg:Er:LiNbO3晶体的光损伤阈值和红外光谱,采用Czochralski技术生长出优质的Mgx:Ery:LiNbO3(x=0.02,0.04,0.06,0.08,y=0.01(摩尔分数))晶体。通过实验得出Mg(0.06):Er:LiNbO3和Mg(0.08):Er:LiNbO3晶体抗光损伤阈值比LiNbO3晶体提高2个数量级以上,且它们的红外光谱OH-吸收峰移到3535cm-1附近;在波长510nm~580nm范围内得到Mg:Er:LiNbO3晶体稳态发射谱。结果表明,Mg2+浓度增加抗光损伤能力增加,掺进摩尔分数为0.04的MgO是Mg:Er:LiNbO3晶体寿命最长的晶体。     

The mechanism of the UV bandedgephotorefractivity suppression in highly doped LiNbO3:Zr crystals

The ultraviolet (UV) band edge photorefractivity of LiNbO3:Zr at 325 nm has been investigated. The experimental results show that the resistance against photorefraction at 325 nm is quite obvious but not as strong as that at 351 nm, when the doping concentration of Zr reaches 2.0 mol%. It is reported that the photorefractivity in other tetravalently doped LiNbO3 crystals, such as LiNbO3:Hf and LiNbO3:Sn, is enhanced dramatically with doping concentration over threshold. Here we give an explicit explanation on such seemly conflicting behaviors of tetravalently doped LiNbO3, which is ascribed to the combined effect of increased photoconductivity and the absorption strength of the band edge photorefractive centers.     

六角形单块铌酸锂电光Q开关

一 单块双45°电光Q开关虽然有很多优点,特别是它能自然光调制,对中小型激光功率器件的应用很方便,但它还存在一些缺点,需要完善提高,这种Q开关中o光、e光分离角较大,造成了消光比低。对石榴石等高增益工作物质往往因消光比低而“关不死”。对铌酸锂双45°单块电光Q开关,实际应用中大多采用偏光瞬时加电压工作方式,这样工作电压比退电压方式高二倍,特别是效率降低约一倍,不能充分发挥单块Q开关自然光调制、效率高等优点。本文介绍的六角形单块电光Q开关克服了这些缺点,保留了它的优点。     

In0.53Ga0.47As liquid phase epitaxy on (100)-InP substrates at low growth temperatures

In0.53Ga0.47As epitaxial layers of high quality and excellent surface morphology have been grown in an automated LPE system. The growth temperature was varied between 500 and 63O°C. Room-temperature Hall measurements indicated a net carrier concentration of n = 8 × 1014 cm?3 and mobility values of ? = 13000 cm2V?1 s?1 at TG 617°C and n = 7.7 × 1015 cm?3 and ? = 9800 cm2 V?1 s?1 at TG = 517°C, respectively.     

Low-loss optical stripe waveguides in LiNbO3 formed by He+ implantation

We report the fabrication of low-loss stripe optical wave-guides in LiNbO 3by He+ implantation. At a wavelength of 633 nm the waveguides were found to have a propagation loss as low as l-OdBcm?1, dependent on the make-up of the vertical waveguide walls. These waveguides were also found to exhibit no photorefractive effects.     

Ion implanted optical waveguides in LiNbO3

The fabrication of low loss single mode integrated optical waveguides by the implantation of He+ ions in LiNbO3 is reported. An assessment is made of the processing requirements in terms of implantation energy, ion dose and annealing parameters. Consideration is also given to the use of multienergy implants as a means of improving isolation between waveguide and substrate. Results on single mode planar waveguides show propagation losses below 1 dB cm?1 for laser light of 632.8 nm wavelength.     

非晶态SiO2过渡层对生长C轴取向LiNbO3薄膜的影响

采用磁控溅射方法,在Si衬底和LiNbO3薄膜之间引入SiO2过渡层制备LiNbO3薄膜。采用X射线衍射（XRD〉、傅里叶变换红外吸收光谱（FT-IR）和扫描电子显微镜（SEM）对LiNbO3薄膜的结晶取向、组成成分和表面形貌进行了表征,重点研究了非晶态SiO2过渡层对LiNbO3薄膜C轴取向的影响。结果表明,非晶态S...