光纤陀螺调制器的残余强度调制影响与消除

光纤陀螺(IFOG)用相位调制器的残余强度调制(RIM)直接影响标度因子稳定性.对Y波导调制器残余强度调制特性进行了实验测试,根据测试结果给出了残余强度调制特性的近似公式.对开环光纤陀螺,在调制器存在内静电压时,残余强度调制对标度因子稳定性影响的大小与调制器两分支残余强度调制系数的差和内静电压成正比;对数字闭环方式,残余强度调制不仅直接影响标度因子稳定性,也影响由2π复位环路确定的调制信号最高电压而间接影响标度因子稳定性,影响的大小与调制器两分支残余强度调制系数的差成正比,但与电光系数成反比.提出的三时隙解调方法不仅能消除残余强度调制的直接影响,也能消除通过2π复位环路的间接影响.     

Y波导调制器半波电压及调制相位漂移研究

分析了用于光纤陀螺的Y波导相位调制器的半波电压特性及其对光纤陀螺系统特性的影响,测试了温度和光源波长变化对半波电压的影响;阐述了Y波导调制器调制相位漂移对光纤陀螺系统特性的影响,测试了温度以及相对湿度变化对Y波导调制器调制相位漂移的影响.针对实验结果提出了改进Y波导制作工艺的措施.     

宽带导波声光Bragg调制器

我们在Ti扩散Y切LiNbO_3光波导上设计并制作了三种导波声光Bragg调制器.这些AO器件分别具有50MHz,100MHz和200MHz的调制带宽.     

波导光电器件的微波有效折射率——器件微波折射率

以波导电光调制器芯片结构为例 ,利用点匹配法计算调制器芯片的电场分布 ,从而计算调制器电极的微波有效折射率 ,由此提出了器件折射率的概念。进一步证明了当光电信号互相匹配时调制带宽可达 10 0GHz。     

利用相位和强度调制器产生高消光比超短光脉冲

提出了一种产生高消光比超短光脉冲的新方法.利用相位调制器调制连续光生成啾啁光,而后利用M-Z强度调制器的倍频调制抑制对压缩不利的啁啾部分的影响,再通过等效啁啾光纤光栅进行压缩产生光脉冲.理论和仿真结果表明,该方法可以很好地消除光脉冲的基底及减小旁辦,产生消光比大于30 dB、波形理想的光脉冲,具有很强的可实现性.最后利用实际制作的色散系数为-380 ps/nm的等效啁啾光纤光栅对该方法进行了实验验证,结果表明,在重复频率为2.5 GHz、相位调制系数为9时,可产生脉宽小于18 ps的高质量光脉冲.     

基于铌酸锂调制器的超短光脉冲源的研究

提出了一种基于商用化的铌酸锂调制器产生超短光脉冲的方法.直流光依次经过相位调制器和强度调制器调制,利用色散补偿光纤(DCF)和梳状色散光纤链(CDPF)对调制产生的光脉冲分别进行啁啾补偿、非线性压缩.压缩后的光脉冲注入高非线性光纤(HNLF),利用其自相位调制效应(SPM)展开脉冲光谱后滤波,可以有效地消除光脉冲的基座,实现光脉冲的整形.获得了10GHz的1.8ps无基座近变换极限光脉冲.     

半导体行波光放大器作光相位调制器的研究

本文主要研究TWA的一个重要的非线性应用:TWA用作光相位调制器。这是一种有源增益波导光相位调制器。其调制原理是通过改变TWA有源区载流子浓度,引起介质折射率的相应变化,从而实现对注入光载波的相位调制。与光源波导相位调制器     

倒置共面波导行波调制器的理论分析

本文提出了一种新颖的集成光波导行波调制器结构。该结构利用倒置菜面波导作为调制器的外调制电路，减少了光波和调制波之间的速度失配，提高了调制带宽，文中采用谱域等效传输线方法分析了倒置共面波导传输的传播特性。     

基于电光调制器的全Stokes矢量的遥感测量

在利用光学方法测量参数的技术领域,偏振光的调制和检测具有重大的实用价值.但目前的偏振遥感主要是线偏振参数的测量,不是全Stokes矢量的测量.为实现全矢量图像的测量和显示,需要构建一种应用于遥感测量的全偏振图像采集、存储、计算和显示系统.整个全偏振测量装置的核心是一个包含液晶调制器的双CCD成像装置.系统通过对液晶调制器的控制,对入射光进行相位调制,偏振分光棱镜将调制后的光束分为强度相等的两束光(o光和e光),并由两个CCD进行图像的实时同步采集,最后由数字信号处理器(DSP)进行全Stokes参数的计算并输出结果图像.实验结果表明:全Stokes矢量图像包含更多的图像信息,在目标识别和其他图像测量的应用上将会发挥巨大的作用.     

新型声光波导调制器中声波导厚度的设计理论

介绍了一种新型的声光波导调制器,针对声光波导调制器中声波导厚度的大小影响在其中传播的声表面波速度从而影响调制器的开关速度的问题,提出了一种声波导厚度设计的理论模型.在该理论模型下,用matlab软件计算了以Y切Z传LiNbO3为衬底,在其表面镀Z切X传ZnO声波导的声光波导调制器,得到了声表面波波速与声波导厚度的关系,为调制器中声波导的设计提供了依据.     

Signal correlation using a one-dimensional electroabsorptive CCD spatial light modulator

Electrically addressed spatial light modulation (SLM) may be carried out in a GaAs charge-coupled device (CCD) by charge-transfer control of the electroabsorption in the individual storage wells. One-dimensional modulator arrays may be utilized in both space-integrating and time-integrating correlators operated as incoherent optical processors. In the space-integrating case, one SLM controlled by the input signal is operated in cascade with a second SLM controlled by a reference waveform. This arrangement yields a single-detector output which is the correlation as a function of time. In the time-integrating correlator, the input signal is carried by the light source while a single SLM with a traveling reference wave controls the output intensity to a detector array. The modulator arrays may be operated with the light at normal incidence to a CCD with transparent gates or in a guided-wave mode, where the light propagates beneath the gate electrodes and parallel to the surface. The calculated dynamic range is greater for the guided-wave case because of the greater depth of modulation, although the fabrication and optical coupling are more critical. Space-integrating correlator performance is limited by "bleaching" or well-filling by the modulated light and predicted dynamic ranges are 20 dB for normal-incidence operation and 40 dB for the guided-wave mode. In the time-integrating correlator, saturation of the detector array is limiting, but the 100-percent modulation available in the input optical source yields 35-dB dynamic range for normal-incidence and 55 dB for guided-wave operation.     

Active mode locking of an erbium-doped fiber laser using anintracavity laser diode device

A ridge waveguide, GaInAsP semiconductor laser chip has been used intracavity as a loss modulator in an erbium-doped fiber laser. Operating at modulation rates of around 500 MHz, typical pulse durations of 40 ps were obtained, with average output powers of up to 10 mW     

LiNbO3 optical intensity modulator packaged with monitorphotodiode

The assembly technique to simply install a monitor photodiode (PD) with a LiNbO₃ (LN) Mach-Zehnder modulator in the same package is proposed. A light radiated from the Mach-Zehnder Y-branch toward the LN output facet is lead into a glass bead, which is bonded to the LN facet as a fixture of the optical fiber. The end of the glass bead is cut to have an angled face, and the radiated light is reflected normal to the LN waveguide axis and toward the PD fixed on the side of package. The curved surface of the glass bead is effective to roughly focus the light onto the PD. We demonstrate that such monitor PD outputs an intensity modulation exactly reverse to the LN output modulation with a sensitivity higher than 0.03 A/W per optical output power of LN, indicating a usability of the PD output to monitor the drift of LN modulator     

光载微波信号抗大气干扰的研究

为了研究射频强度调制激光信号光源的参量,特别是调制深度对调制波的抗干扰能力产生的影响,采用干涉法对射频强度调制激光信号在通过大气湍流干扰后其相位的变化进行了理论分析和实验验证。搭建了Mach-Zehnder干涉仪,参加干涉的两束光分别为未经调制的单频光和调制后的双频光。以干涉条纹对比度作为信号相位起伏的衡量标准,比较不同大气湍流干扰条件下,干涉条纹的对比度随调制深度的变化。大气湍流由空间光调制器模拟产生,分别在26.32%,42.04%,67.59%和85.04% 4种调制深度下,比较有无大气湍流时干涉条纹的对比度的变化。结果表明,调制信号的调制度越深,其抗大气湍流干扰的能力越强。该结论对双频激光雷达光源的选择具有一定的参考意义。     

高精度温控脉宽调制工作方式与频谱问题研究

介绍了几种用于光纤陀螺光源的高精度温度控制的脉宽调制（PWM）工作方式,并分析了这几种工作方式的驱动转换过程。对于脉宽调制方式引入的电磁干扰问题,详细分析了转换交越过程中的输出信号及频谱。研究发现,在脉宽调制工作的交越过程中,输出信号的频率和脉宽是复杂的、无规律的,其谱线位置发生了随机的、不可预测的变化,功率分布不再符合周期矩形脉冲谱特性。针对这种交越随机频谱引入的电磁干扰,提出了几种有效的解决方案,并给出了一种方案的实验验证。     

Ridge Waveguide Electro-Optic Polymer Modulator with a New Kind of Corona Poled Crosslinkable Polyurethane

制备了一种全部以聚合物为波导材料的电光调制器,其中芯层为新型可交联极化聚胺脂电光功能材料．旋涂制备波导薄膜、电晕极化产生非线性、光刻和氧反应离子刻蚀完成脊波导为主要的工艺步骤。1.3μm光源光纤耦合输入脊波导调制器,得到很好的输出端单模近场图及清晰的低频调制信号．     

基于DSP的超磁致伸缩换能器驱动电源设计

为了提高稀土超磁致伸缩换能器驱动电源的效率以及实用性,采用DSP器件TMS320F2812作为主控芯片,结合混合脉宽调制方法实现SPWM波形。采用半桥型逆变电路实现SPWM的功率放大,并对隔离驱动电路、反馈电路和滤波匹配电路进行合理而有效的设计,保证了换能器的输出效能。同时使用电流控制频率的方法实现谐振频率的自动跟踪。实验证明,该驱动电路输出频率稳定,波形失真度低,且能量转换效率较高。     

Monolithically integrated resonator microoptic gyro on silicaplanar lightwave circuit

We report a novel configuration of resonator microoptic gyro (MOG), which is monolithically integrated on silica planar lightwave circuit (PLC) with countermeasures for noise factors. Optical ring-resonator gyros suffer mainly from polarization fluctuation induced noise and backscattering induced noise. We discuss eigenstate of polarization in the waveguide to clarify behavior of the former and propose a countermeasure with control of the waveguide birefringence. As for the latter, binary phase shift keying (B-PSK) with a special signal processing is proposed. Thermooptic (TO) phase modulation is the only one scheme to apply B-PSK in the silica waveguide, whose bandwidth is limited to ~1 KHz. To utilize the narrow bandwidth of the TO modulator effectively, we propose an electrical signal processing scheme and a modulation waveform to compensate the frequency response. By constructing an experimental setup, suppression of the backscattering induced noise is demonstrated, and the gyro output is observed with applying an equivalent rotation