基于光纤马赫-曾德尔干涉仪的强度测量研究

根据光外差检测原理，分析得到干涉测量适用于信号光强小于参考光强的探测，直接测量适用于信号光强大于参考光强的探测的结论。利用自制的全光纤马赫-曾德尔干涉仪系统，对位移信号进行了测量。实验结果表明：当位移信号较小时，干涉测量的灵敏度分别为62．068μW／mm和9．90mV／mm，而非干涉测量的灵敏度分别为4．30μW／mm和0．35mV／mm；当位移信号较大时，干涉测量的灵敏度分别为2．643mV／mm和0．055mV／mm，非干涉测量的灵敏度分别为12．326mV／mm和4．194mV／mm，测量结果与分析得到的结论一致。对于光纤干涉仪强度调制检测的应用具有参考价值。     

全光纤马赫-曾德尔干涉仪的测温实验

阐述了全光纤马赫-曾德尔干涉仪的测温原理,并在20~40℃对测温系统进行了标定.利用Matlab数字图像处理技术对温度干涉条纹图像进行处理,设计了计算条纹移动数目的程序.通过测温实验对条纹记数程序进行了检验,有较好的准确度.     

基于量子增强型光纤马赫-曾德尔干涉仪的低频信号测量

利用低频光通信波段真空压缩态光场可实现基于光纤的量子精密测量.本文利用简并光学参量振荡器实验制备出1550 nm低频真空压缩态光场.在分析频段10—500 kHz范围内压缩态光场的压缩度均达3 dB.用实验制备的1550 nm真空压缩态光场填补光纤马赫-曾德尔干涉仪的真空通道,实现了量子增强型光纤马赫-曾德尔干涉仪,完成了突破标准量子极限的相位调制频率为500 kHz的低频信号测量.与光纤马赫-曾德尔干涉仪相比,测量信噪比提高了2 dB.     

基于全光纤马赫-曾德尔干涉仪的微位移传感研究

研究了一种基于全光纤马赫-曾德尔(Mach-Zehnder)十涉仪的高灵敏度微位移传感器，将干涉仪的一个臂固定在微动平台上，在消除环境干扰的情况下，通过对丁涉仪臂的拉伸，从光谱仪观察干涉谱线中某一特定波长的移动与拉伸长度成正比，从而实现一种位相调制型微化移传感器。当化移变化0．0020mm时，波长移动了0．61nm，调谐速率为305nm／mm，线性拟合度为0．9994。     

基于马赫-曾德尔干涉仪的单个光子操控

分别利用空间和光纤马赫—曾德尔干涉仪对空间和光纤传输中的单个光子的干涉现象进行了研究,干涉对比度可达到90％以上,实现了空间和光纤中的单个光子的路由操控。实验采用脉冲调制加衰减的方法产生单个光子,获得了每个脉冲中只包含0．1个光子的准单光子源。通过改变压电换能器的电压控制马赫—曾德尔干涉仪的单个光子在两个输出端的选择,实现了光子在节点上的路由。采用同步符合检测技术,利用重复频率为1kHz,脉冲宽度为100ns的同步信号对输出信号进行符合,实现了量子效率高于70％,暗计数小于0．2s^-1的单光子高灵敏度检测,观测到了单个光子在相位操控下出射到两个输出端的有序分配现象。验证了基于马赫—曾德尔干涉仪的单个光子路由操控实现的可能性。     

耦合环形腔马赫-曾德尔干涉仪瞬态响应及应用

对耦合环形腔马赫-曾德尔干涉仪光脉冲瞬态响应进行了理论和数值研究.利用光束追迹法推导了脉冲传输的解析关系,并数值模拟了传输光场随时间的演化.输出脉冲形状可通过控制损耗进行调解,响应速度为皮秒量级.由于马赫-曾德尔干涉仪两输出端口的互补性,在输出端可同时实现光脉冲微分和积分操作.利用损耗控制机制,可实现单通道脉冲微分和积分操作转换.引入增益补偿损耗,可实现脉冲压缩及产生可调单一触发光脉冲.     

孔型硅光子晶体中折叠式马赫-曾德尔干涉仪(英文)

设计了基于孔型硅光子晶体的折叠式马赫-曾德尔干涉仪.它由一个光反射器和几个光分束器构成.在干涉仪中,窄光束依赖自准直效应进行传输.利用时域有限差分法研究了折叠式马赫-曾德尔干涉仪的特性.结果表明,在0.255～0.270c/a的归一化频率范围内,干涉仪的两个透射谱均为正弦形且强度互补,透射谱的透射峰间距随着干涉仪两臂的光程差的增大而减小.该折叠式干涉仪结构紧凑,尺寸比非折叠式光子晶体马赫-曾德尔干涉仪要小许多,有望作为信道解复用器应用于光子芯片中.     

孔型硅光子晶体中折叠式马赫-曾德尔干涉仪

本文首次设计了基于孔型硅光子晶体的折叠式马赫-曾德尔干涉仪。它由一个光反射器和几个光分束器构成。在干涉仪中,窄光束依赖自准直效应进行传输。利用时域有限差分法研究了折叠式马赫-曾德尔干涉仪的特性。结果表明,在0.255-0.270c/a的归一化频率范围内,干涉仪的两个透射谱均为正弦形且强度互补,透射谱的透射峰间距随着干涉仪两臂的光程差的增大而减小。该折叠式干涉仪结构紧凑,尺寸比非折叠式光子晶体马赫-曾德尔干涉仪要小许多。它有望作为信道解复用器应用于光子芯片中。     

基于双光栅的马赫-曾德尔干涉仪的初步研制

设计和初步制备了基于双光栅的等臂和不等臂马赫-曾德尔干涉仪,两个衍射光栅分别用作光束分裂器和光束复合器.来自激光器的平行光束透过第一光栅后产生多柬衍射光,等臂干涉仪使用两个平面反射镜反射两束对称衍射光至第二光栅的同一位置并产生完全重合的衍射条纹,即每束衍射光包含两个成分.利用光探测器监测任一束重合的衍射光束,该光束两成分之间的相位差随时间的变化就能够被准确测定.而不等臂干涉仪仅使用一个反射镜反射某一束衍射光并使之与零级光束透过第二光栅后产生完全重合的衍射条纹.通过使用一个厚度为50μm的玻璃片来改变相位差,对不等臂干涉仪的干涉效果进行了测试,得到了与理论值相符的实验结果.     

基于全光纤马赫-曾德尔干涉仪的压力和温度传感实验

对基于马赫-曾德尔干涉技术的光纤压力和温度传感特性的进行了研究。利用自制的全光纤干涉仪,对不同温度条件下的压力变化和不同压力下的温度变化引起的光功率的变化进行了测量和分析,给出该系统在无压力时温度测量范围是39~46℃;1N压力下,温度在40~45℃变化时,温度线性灵敏度为-4 078.7nW/℃,线性相关系数为0.976 6。45℃时,光功率随压力变化灵敏度为-1.162 1μW/N,线性相关系数0.989 3。结果表明系统在40~45℃和0~1N范围内,具有较好的温度和压力检测特性。     

Compact temperature-insensitive modulator based on a silicon microring assistant Mach-Zehnder interferometer

<正>On the silicon-on-insulator platform,an ultra compact temperature-insensitive modulator based on a cascaded microring assistant Mach-Zehnder interferometer is proposed and demonstrated with numerical simulation.According to the calculated results,the tolerated variation of ambient temperature can be as high as 134℃while the footprint of such a silicon modulator is only 340μm~2.     

Instantaneous frequency measurement based on complementary microwave photonic filters with a shared Mach-Zehnder interferometer

A novel configuration using only one Mach-Zehnder interferometer (MZI) for photonic-assisted instantaneous microwave frequency measurement is proposed. The amplitude comparison function (ACF), related to the input microwave frequency while independent of the input optical power and modulate index, is achieved by using a ratio of low-pass to bandpass frequency responses introduced by intensity and phase modulation with a shared MZI. The microwave frequency can be estimated by the measured ACF. A proof-of-concept experiment for measurement of RF from 5 to 10 GHz is successfully demonstrated with the measurement errors less than ± 0.2 GHz.     

Highly sensitive bend sensor based on Mach-Zehnder interferometer using photonic crystal fiber

Optical fiber bend sensor with photonic crystal fiber (PCF) based Mach-Zehnder interferometer (MZI) is demonstrated experimentally. The results show that the PCF-based MZI is sensitive to bending with a sensitivity of 3.046 nm/m⁻¹ and is independent on temperature with a sensitivity of 0.0019 nm/°C, making it the best candidate for temperature insensitive bend sensors. To that end, another kind of bend sensor with higher sensitivity of 5.129 nm/m⁻¹ is proposed, which is constructed by combining an LPFG and an MZI with zero offset at the second splice mentioned above.     

Enhanced phase sensitivity with a nonconventional interferometer and nonlinear phase shifter

We propose a theoretical scheme of an enhanced phase sensitivity by introducing a nonlinear phase shifter to the nonconventional interferometer consisting of a balanced beam splitter (BBS) and an optical parameter amplifier (OPA), a modified nonlinear interferometer (MNI). Then we use coherent state and even coherent state as inputs and homodyne detection at one output port of the MNI for phase sensitivity, both without and with photon losses. We find that the nonlinear phase shifter can not only improve phase sensitivity, but also significantly resist the decoherence from photon losses. In comparison to both the BBS+OPA scheme with linear phase shifter and the traditional Mach–Zehnder interferometer with nonlinear one, the phase sensitivity of the MNI scheme shows the best performance. It is interesting that the nonlinear phase shifter can stimulate potential of the OPA, although there is no improvement in signal-to-noise ratio beyond standard quantum limit for the BBS+OPA scheme with a linear phase shifter.     

Tunable double-clad ytterbium-doped fiber laser based on a double-pass Mach-Zehnder interferometer

We have demonstrated an adjustable double-clad Yb³⁺-doped fiber laser using a double-pass Mach-Zehnder interferometer. The laser is adjustable over a range of 40 nm from 1064 nm to 1104 nm. By adjusting the state of the polarization controller, which is placed in the double-pass Mach-Zehnder interferometer, we obtained central lasing wavelengths that can be accurately tuned with controllable spacing between different tunable wavelengths. The laser has a side mode suppression ratio of 42 dB, the 3 dB spectral width is less than 0.2 nm, and the slope efficiencies at 1068 nm, 1082 nm and 1098 nm are 23%, 32% and 26%, respectively. In addition, we have experimentally observed tunable multi-wavelengths lasing output.     

相干与信息守恒及其在Mach-Zehnder干涉中的应用

自量子力学诞生以来,相干性和互补性一直是被广泛而深入研究的两个重要课题.随着量子信息近年来的发展,人们引入了若干度量来定量地刻画相干性和互补性.本文建立两个信息守恒关系式,分别基于"Bures距离-保真度"和"对称-非对称",并且利用它们来刻画相干性和互补性.具体来说,首先从信息守恒的观点解释Bures距离和保真度的互补关系,并由此自然推导出Mach-Zehnder干涉仪中的Englert"干涉-路径"互补关系.其次在量子态和信道相互作用的一般框架中讨论"对称-非对称"信息守恒关系,并揭示其与Bohr互补性和量子相干性的内在联系.最后,在Mach-Zehnder干涉仪中探讨相干、退相干及互补性,刻画两个信息守恒关系之间的密切联系.     

Polarization beam splitter based on photonic crystal self-collimation Mach-Zehnder interferometer

A polarization beam splitter based on a self-collimation Mach-Zehnder interferometer (SMZI) in a hole-type silicon photonic crystal was proposed and numerically demonstrated. Utilizing polarization dependence of the transmission spectra of the SMZI and polarization peak matching (PPM) method, the SMZI can work as a polarization beam splitter (PBS) by selecting appropriate path length difference in the structure. Because of its intrinsic operating principle, the PBS possesses high polarization extinction ratios (PERs). As its dimensions are only several operating wavelengths, the PBS may have practical applications in photonic integrated circuits.     

Tilting and shearing determination in the alignment of a Mach-Zehnder interferometer by zone plates

An easy and accurate method to detect the kind of disarrangement and its magnitude in the adjustment process of a Mach-Zehnder interfermeter by means of an equilateral hyperbolic zone plate is explained.     

晶格旋转光子晶体Mach-Zehnder干涉结构传感特性

基于光子晶体的自准直效应,利用在同一背景折射率下不同介质柱的等效折射率的不同,提出了一种基于晶格旋转的二维光子晶体Mach-Zehnder干涉仪折射率传感器。分别应用线缺陷和空气平板波导构成其分束镜和全反镜,并在其中一个干涉臂上设置传感区域。通过改变填充到传感区域溶液的浓度,改变介质柱的折射率,进而影响透射谱的中心波长,从而建立起溶液浓度和透射波长之间的数学关系;并进行了酒精溶液浓度测量的数值模拟,结果表明,该传感器在1.33~1.37折射率变化范围内灵敏度为250nm/RIU。