High-Q micro-ring resonators and grating couplers for silicon-on-insulator integrated photonic circuits

An ultra-small integrated photonic circuit has been proposed,which incorporates a high-quality-factor passive micro-ring resonator(MR) linked to a vertical grating coupler on a standard silicon-on-insulator(SOI) substrate.The experimental results demonstrate that the MR propagation loss is 0.532 dB/cm with a 10μm radius ring resonator,the intrinsic quality factor is as high as 202.000,the waveguide grating wavelength response curve is a 1 dB bandwidth of 40 nm at 1540 nm telecommunication wavelengths,and the measured fiber-to-fiber coupling loss is 10 dB.Furthermore,the resonator wavelength temperature dependence of the 450 nm wide micro-ring resonator is 54.1 pm/℃.Such vertical grating coupler and low loss MR-integrated components greatly promote a key element in biosensors and high-speed interconnect communication applications.     

High sensitivity optical detection method based on photon RF oscillator

Based on the research of optical coherent detection in complex background, a new type of laser superheterodyne detection method was proposed, which based on a photon radio frequency technology. Firstly a system by photon RF oscillation mechanism and mathematical model was constructed. The principle of constructing the system was deduced and analyzed. The correctness of the method was verified by theoretical simulation and experiment. Compared with the traditional technology, the proposed method can improve the sensitivity of optical detection by several orders of magnitude, and can effectively suppress the influence of background dispersion spectrum on target information detection.     

基于载波抑制单边带调制的微波光子混频方案

为了克服电混频器的瓶颈,实现大带宽的信号混频,提出了一种基于双偏振双平行马赫-曾德尔调制器的微波光子混频方案。通过调节调制器的6个直流偏置电压进行载波抑制单边带调制,射频(RF)信号和本振(LO)信号分别注入调制器,相互隔离,各自调制,且在2个相互正交的偏振态上传输,最后经偏振控制器和检偏器调整到同一偏振态上进行拍频,上、下变频模式的切换只需要改变其中一个直流偏置电压。仿真与实验表明:该方案切实可行,输入的RF频率在11~25 GHz时,输出的上变频或下变频信号的RF杂散抑制比不低于25 dB,频谱纯度高,可调谐性好,变频模式之间切换方便,系统的RF/LO隔离度达到-49 dB。     

Multi-band microwave photonic satellite repeater scheme employing intensity Mach-Zehnder modulators

To solve the satellite repeater's flexible and wideband frequency conversion problem, we propose a novel microwave photonic repeater system, which can convert the upload signal's carrier to six different frequencies. The scheme employs one 20 GHz bandwidth dual-drive Mach-Zehnder modulator (MZM) and two 10 GHz bandwidth MZMs. The basic principle of this scheme is filtering out two optical sidebands after the optical carrier suppression (OCS) modulation and combining two sidebands modulated by the input radio frequency (RF) signal. This structure can realize simultaneous multi-band frequency conversion with only one frequency-fixed microwave source and prevent generating harmful interference sidebands by using two corresponding optical filters after optical modulation. In the simulation, one C-band signal of 6 GHz carrier can be successfully converted to 12 GHz (Ku-band), 28 GHz, 34 GHz, 40 GHz, 46 GHz (Ka-band) and 52 GHz (V-band), which can be an attractive method to realize multi-band microwave photonic satellite repeater. Alternatively, the scheme can be configured to generate multi-band local oscillators (LOs) for widely satellite onboard clock distribution when the input RF signal is replaced by the internal clock source.     

激光陀螺射频激励的激励特性研究

本文给出了射频激励激光陀螺的功率输出和Ｈｅ－Ｎｅ气压,气比关系的实验结果,同时给出了一个实用的射频激励源电路,并帝测了它的输出特性。     

Recent progress in integrated electro-optic frequency comb generation

Optical frequency combs have emerged as an important tool enabling diverse applications from test-and-measurement,including spectroscopy,metrology,precision distance measurement,sensing,as well as optical and microwave waveform synthesis,signal processing,and communications.Several techniques exist to generate optical frequency combs,such as mode-locked lasers,Kerr micro-resonators,and electro-optic modulation.Important characteristics of optical frequency combs include the number of comb lines,their spacing,spectral shape and/or flatness,and intensity noise.While mode-locked lasers and Kerr micro-resonators can be used to obtain a large number of comb lines compared to electro-optic modulation,the latter provides increased flexibility in tuning the comb spacing.For some applications in optical communications and microwave photonics,a high degree of integration may be more desirable over a very large number of comb lines.In this paper,we review recent progress on integrated electro-optic frequency comb generators,including those based on indium phosphide,lithium niobate,and silicon photonics.     

基于交叉增益调制的全光单边带上变频研究

提出了一种基于交叉增益调制的全光单边带上变频新技术,对射频信号的全光处理具有独特优势,设计了单边带上变频的光载无线通信系统,并进行实验验证,仿真结果表明,在光纤上传输前后的眼图无明显差异,在经过长度超过25 km 的光纤传输后,系统光功率损耗为1．8 dB,系统误码率为10－9。     

一种新型基于MIM等离子体环形谐振器的可调谐高性能多信道波分解复用器的设计

设计并研究了基于金属-介质-金属等离子体环形谐振器的可调谐高性能多通道波分解复用器。通过环形腔的谐振理论分析,发现通过调节环形腔的半径和填充介质折射率可以很容易地控制波分复用器的信道波长,与有限元法模拟得到的结果吻合得很好。由等离子体波导和多个环形谐振器组成的多信道WDM结构增加了在电信波长的传输率,传输率高达80%,比最近文献中报道的结果高出两倍。所设计的多信道波分解复用器在高集成电路中有重要潜在应用。     

基于相位校正的高稳定射频信号光纤传输

提出了一种新的基于相位校正的高稳定射频信号光纤传输方案,在本地终端采用一个本地振荡器和两个混频器,远端接收的射频信号与本地终端信号相比只有很小的抖动.建立了20km传输实验系统,在一根2 0km的单模光纤上传输6GHz的射频信号,系统相位残余抖动不超过1.33ps.     

ROF系统中单边带光载OFDM信号传输性能研究

研究了一种光纤无线通信系统中用单边带产生光载波并传输的OFDM-ROF方案.将2Gbit/s的OFDM信号与10GHz的射频信号混频驱动电光调制器,产生单边带调制信号,调制后的信号经光纤传输至基站,通过光电转换后再进行无线传输.实验证实,2Gbit/s的基带OFDM信号在10GHz-ROF系统中通过光纤传输200km后不经无线传输,其功率代价仅为1dB.不经过光纤仅经过8m无线传输后功率代价大约只有0.3 dB.产生的信号既经过200km光纤传输又经过8m无线传输后接收星座图也很好.     

基于相位-强度调制转换的光纤色散精确测量方法

在分析光纤色散导致的相位-强度调制转换的基础上,提出了一种利用电光相位调制的光纤色散扫频测量方法。方法的原理为光纤色散使相位调制信号获得附加相移并产生周期性衰落,从衰落曲线的特征性凹陷频率确定出光纤色散。实际运用中,由于凹陷频率附近的信号弱,因此噪声大且不稳定。为了解决这一问题,通过衰落曲线的多项式拟合,进一步提高凹陷频率和光纤色散的测量精度。实验中,对长光纤或者短光纤分别测试以验证本文方法对于不同色散的适应性。实验结果表明,本文方法的相对误差小于0.22%。使用矢量网络分析仪(VNA)和相位调制器进行测试,可工作于不同光波长,适用于测量不同种类的光纤的色散;并且可以利用简单的实验系统,实现光纤色散的大小和符号的测量。     

基于倍增FSR式光梳状滤波器阵列的瞬时频率测量研究

基于自由频谱区(FSR)倍数增长式光梳状滤波器阵列,设计了一种微波瞬时频率测量方案,实现了具有自然二进制编码的数字输出。待测微波信号经过载波抑制型单边带调制后加载到光波上产生一阶边带,而后将其输入到光梳状滤波器阵列中;阵列由多个梳状滤波器并联而成,它们滤波响应对应的FSR呈倍数增长趋势,最高位数字输出对应滤波器的FSR最大。滤波后输出的光信号经光电检测、比较和判决后,获得N位自然二进制码标识的频率值,提高了编码效率和测量精度。最后,在0～40GHz范围,验证了4位有效长度的数字编码式测频结果。     

可调RF信号光传输系统相位噪声优化设计

为了优化宽泛可调的低频基准射频信号系统、降低射频生成系统的相位噪声,采用减少部件的优化设计方法,使用调幅器改善相位噪声,实现了系统设计的简化。经过理论分析和实验验证,取得了低频射频信号条件下的系统相位噪声与频率偏移数据。结果表明,可以通过机械隔离来消除由于光纤振动产生的过量相位噪声。这在未来的光通信领域中具有一定的应用价值和实际意义。     

射频信号光纤传输技术研究现状及进展

随着现代战场中电磁环境的日趋复杂化,情报侦察、电子对抗、通信和遥感等系统中不同频率、制式的射频(RF)信号密集交叠,RF信号光纤传输技术所具有的宽带、抗干扰和信号损耗小等优势将在这些系统中发挥关键性的作用。概述了RF信号光纤传输技术的特点和优势,介绍了国内外的研究现状及进展情况,展望了RF信号光纤传输技术的发展前景。     

射频电导轮廓的概念及应用

提出了粗糙表面射频电导轮廓的概念及物理意义,介绍了与射频电导轮廓相关的技术指标和测量、计算方法,对射频电导轮廓在分析计算粗糙表面射频等效电导率、优化射频微波器件加工工艺流程等方面的应用情况进行了简介。实验表明,研究成果与实测数据相吻合。     

基于偏振复用技术的载边比可调光单边带RoF系统

为提高单边带光载无线通信(RoF)系统倍频及载 边比(OCSR)调谐能力,利用马赫-曾德 尔调制器(MZM)和光纤布拉格光栅(FBG),提出了一种基于偏振复用技术的载边比可调光单边 带调制方案,通过调整偏振控制器(PC)偏振角度即可实现大动态范围的载边比调谐。理论分 析了方案的基本原理,讨论了相关参数对载边比调谐特性的影响,理论研究与实验结果较为 一致。结果表明在误码率(BER)为10－9时,当载边比从4.35 dB调谐到0dB并经50 km光纤传输后接收机灵敏 度可提高1.31 dB。     

High-selectivity single-ended and balanced bandpass filters using ring resonators and coupled lines loaded with multiple stubs

High-selectivity single-ended and balanced bandpass filters (BPFs) using dual-mode ring resonators and coupled lines loaded with multiple stubs are proposed in this paper. With the help of the loaded short-circuited and open-circuited stubs, six deep transmission zeros (TZs) from 0 to 2f₀ (f₀: center frequency of the passband) can be realized in both of single-ended and balanced BPFs to improve the stopband suppressions. The functions of the loaded short/open stubs and calculated analysis of TZs’ positions have been presented. For further demonstration, two examples of single-ended BPF and balanced BPF with high common-mode suppression are designed and fabricated, whose center frequencies are both at 2.1 GHz. Their measured 3-dB fractional bandwidths are 23.7% and 24.7% (differential-mode), respectively. The simulated results and measurements of these two filters are in good agreement.     

30-GHz millimeter-wave carrier generation with single sideband modulation based on stimulated Brillouin scattering

A new technique to generate a millimeter（mm）-wave carrier of 32.57 GHz(f_LO=10.85 GHz) with single sideband modulation（SSB） for radio-over-fiber（RoF） systems is experimentally demonstrated by using stimulated Brillouin scattering（SBS）.The SSB is realized by directly amplifying the +3rd sideband of the modulated optical carrier in the process of SBS.The pump wave is provided through a double Brillouin scattering frequency shifting configuration.The use of the same laser source to generate the pump wave ensures the stability of the mm-wave generation system since the relative frequency shift between them can be eliminated.In addition, the mm-wave carrier obtains an RF power gain of 21 dB with the SBS amplification and a 3-dB bandwidth of 10kHz.     

基于受激布里渊散射的30GHz毫米波单边带调制生成技术

本文提出了一种基于受激布里渊散射原理的单边带调制产生30GHz毫米波的新方法,可应用于光载射频系统。该方法利用一个双布里渊散射移频结构生成泵浦光,并将其反向注入到传输信号光的25 km单模光纤;通过受激布里渊散射,直接放大受调制信号光的正三阶边带,实现光载波的单边带调制,有效改善由色散效应引入的功率涨落问题,保证了毫米波功率稳定。此外,信号光和泵浦光由同一个激光器产生,有效消除两者间的相对频率漂移,从而大大提升了毫米波生成系统的频率稳定性。通过我们的方法,实验系统所生成的毫米波功率增益了21dB,其3dB线宽为10kHz。