Flat-top interleavers using two Gires-Tournois etalons as phase-dispersive mirrors in a Michelson interferometer

We present our experimental investigations of a flat-top 50-GHz optical interleaver using two Gires-Tournois etalons (GTEs) as phase dispersive mirrors in a Michelson interferometer. The spectral characteristics of the interleaver in a 50-GHz channel spacing application exhibit a 0.5-dB passband larger than 43.8 GHz (88% of the spacing), a 25-dB stopband greater than 40 GHz (80% of the spacing), and a channel isolation higher than 30 dB. The result shows that the interleaver interferometer with novel GTE technique can simultaneously produce a 0.5-dB passband and a 25-dB stopband wider than other interferometer techniques.     

Flat-top silica-based arrayed waveguide grating with 40-channels

A wavelength multiplexer or demultiplexer plays ani mportant role in all wavelength division multiplexing( WDM) system.Silica-basedarrayed waveguide gratings(AWGs) offer attractive featuresinthis area due to theadvantage of large output channels and lowlo…     

Silica-based 71-channel arrayed waveguide grating

With the rapid increase of global information capaci-ty,all optical wavelength division multiplexing(WDM)networks are very attractive because they are capable ofprocessing broadband optical signals without convertingthem to electronic signals.Large channe…     

Narrow-channel-spacing 32-channel AWG multiplexer with an innovative alignment method

A 32-channel 50 GHz spaced arrayed-waveguide grating（AWG） with our innovative configuration has been designed and fabricated. The performance of the device has been fully tested by using a system that consists of a tunable laser light source （TLS）, an optical power meter and a polarization controller. The insertion loss （IS） of the device is 4.2-7.4 dB. The crosstalk is about - 28 dB. The IS uniformity is less than 3.3 dB. With our configuration,the performance of the device has been enhanced effectively and the difficulty in alignment process has been decreased obviously.     

Compact Efficient Feed-Horn at 30–38 GHz for a Multi-beam Radio Telescope

The requirements for a feed suitable for a radio telescope multi-beam focal plane array are considered. A smooth-walled spline-profile horn covering the 30–38 GHz frequency band to be used in a multi-beam receiving array of a radio telescope has been optimized, manufactured and tested. The achieved cross-section aperture size of the horn allows us to provide a neighboring beam spacing equal or less than 2HPBW for the RATAN-600 radio telescope. The measured sidelobe levels of the radiation pattern is less than −30dB/−24dB/−26dB in H/E/45⁰-planes, cross-polarization levels better than −20 dB, an input return loss better than −18 dB and the −3dB/−10dB-beamwidths are of the order of 40o/ 80o over the frequency band. Mutual-coupling of adjacent horns is less than −38 dB.     

Analysis of electro-optic switches with series-coupled multiple microring resonators

In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius of the m...     

法布里-珀罗型光学梳状滤波器的设计

提出了一种新型光学梳状滤波器 ,它由双Gires Tournois谐振腔代替Michelson干涉仪的两个全反射镜构成。基于Michelson干涉原理 ,给出了零畸变、高信道隔离度、宽平坦带宽、高一致性、结构简单、性能稳定的光学梳状滤波器的设计原理。设计了信道间隔为 5 0GHz,畸变 <0 0 5dB ,1dB带宽大于 0 38nm ,相邻信道间隔离度大于 2 3dB的光学梳状滤波器     

A 4th order fully integrated active RC complex filter with novel automatic tuning systems

This letter introduces a 4th order active RC complex filter with 1.5MHz center frequency and 1MHz bandwidth. The total harmonic distortion of the filter is less than –60dB and the image rejection ratio is greater than 60dB. A novel technique is also proposed in this letter to automatically adjust the variation of the time constant. The advantages of the proposed method are its high precision and simplicity. Using 5bits control words, the tuning error is less than ±1.6%.     

Thermo-optically tunable arrayed-waveguide-grating made of polymer/Si

Inthe future,optical communication systems will usemore exceptional optical fiber with high bandwidth.Dense wavelength division multiplexing(DWDM)isconsidered as a promising solution to the demand fortransportingterabits ofinformation viafibers[1].Arrayed…     

Septum Polarizer for Ka-Band H-Shaped Rotary Joint

We propose an H-shaped rotary joint that uses septum polarizers. We designed a new polarizer using three-dimensional electromagnetic-field analysis software. We measured the performance of two polarizers connected in series. We found that the insertion loss was less than 0.8 dB, the return loss was less than −15 dB, and the isolation was less than −17 dB in the frequency range 35–41 GHz, corresponding to a fractional bandwidth of ~15%. These results demonstrate the effectiveness of the H-shaped rotary joint.     

Construction and Measurement of a 31.3–45 GHz Optimized Spline-profile Horn with Corrugations

A corrugated spline-profile horn has been designed to meet the stringent specifications and constraints of a receiver for Band 1 (31.3–45 GHz) of the Atacama Large Millimeter Array (ALMA). Given the physical restrictions of the receiver, the horn will be located behind a focusing lens placed 191 mm over its aperture. After this first focusing stage, the horn must have a reflection coefficient less than −20 dB and the cross-polarization not exceeding the −30 dB level in the entire frequency range. The side-lobes should be less than −25 dB at all frequencies and its half power beamwidth must be approximately 24° at 31.3 GHz and 16° at 45 GHz. The horn has been constructed using the split-block technique and characterized in a near-field scanner setup. The results show an excellent performance complying with all the requirements.     

Green phosphorescent organic light-emitting devices based on different electron transport layers combining with fluorescent sub-monolayer

We report a small molecule host of 4,4(-N,N)-dicarbazole-biphenyl (CBP) doped with 8% tris(2-phenylpyridine) iridium (Irppy3) for use in efficient green phosphorescent organic light-emitting devices (PHOLEDs) combined with different electron transport layers of Alq and BAlq. The PHOLEDs exhibit maximum current efficiency and power efficiency of 19.8 cd/A and 6.21 lm/W, respectively. The high performance of such PHOLEDs is attributed to the better electron mobile ability of BAlq and sub-monolayer quinacridone (QAD) as carrier trapping layer and equal charge carrier mobilities of hole and electron to form the broad carrier recombination zone in the emitting layer, which can reduce the triplet-triplet annihilation and improve the efficiency of the device. #$TABThis work has been supported by the Major Project of Science and Technology Office of Fujian Province of China (No.2014H0042), the Natural Science Foundation of Fujian Province of China (No.2015J01664), the Project of Science and Technology Research of Quanzhou in Fujian Province of China (Nos.2013Z125 and 2014Z137), and the 2016 Annual National or Ministries Preparatory Research Foundation Project in Quanzhou Normal University (No.2016YYKJ21). E-mail:yanghuishan1697@163.com      

A 4 mW 3–5 GHz current reuse g<Subscript>m</Subscript>-boosted short channel common-gate CMOS UWB LNA

A novel architecture is presented to optimize the noise performance and the power consumption of the transconductance ‘g_m’ boosted common-gate (CG) ultrawideband (UWB) low-noise amplifier (LNA), operating in the 3–5 GHz range, by employing current reuse technique. This proposed CG LNA utilizes a common source (CS) amplifier as the g_m-boosting stage and the bias current is shared between the g_m-boosting stage and the CG amplifying stage. The LNA circuit also utilizes the short channel conductance g_ds in conjunction with an LC T-network to further reduce the noise figure (NF). The proposed LNA architecture has been fabricated using the 130 nm IBM CMOS process. The LNA achieved input return loss (S₁₁) of −8 to −10 dB, and, output return loss (S₂₂) of −12 to −14 dB, respectively. The LNA exhibits almost flat forward voltage gain (S₂₁) of 13 dB, and reverse isolation (S₁₂) of −62 to −49 dB, with a NF ranging between 3.8 and 4.6 dB. The measurements indicate an input-referred third order intercept point (IIP3) of −6.1 dBm and an input-referred 1-dB compression point (ICP_1dB) of −15.4 dBm. The complete chip draws 4 mW of DC power from a 1.2 V supply.     

High-power superfluorescent source of Yb^3＋ -doped double-cladding photonic crystal fiber

A new type of high-power broadband superfluorescent source of Yb^3＋ -doped double-cladding photonic crystal fiber is reported experimentally, which is pumped at 976 nm by a high-power laser diode with the end-coupling method. We have obtained a smooth broadband output of superfluorescence The maximum output power is 1.649 W with a slope efficiency of 56.7%. The 3 dB bandwidth is 22.4 nm To the best of our knowledge, this is the first report about SFS with such high output power of 1.649 W.     

Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4x4 switch matrix with spot size converters （SSCs） and a new driving circuit are designed and fabricated. The introduction of a spot size converter （SSC） has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than l~s.     

A 2× 2 SOI mach-zehnder thermo-optical switch based on strongly guided paired multimode interference couplers

A silicon-on-insulator 2× 2 Mach-Zehnder thermo-optical switch is developed based on strongly guided paired multimode interference couplers. The multimode-interference couplers were etched deeply for improving coupler characteristics such as self-imaging quality, uniformity and fabrication toierance. The proposed switch achieves good performances, including a low insertion loss of -11.0dB, a fiber-waveguide coupling loss of-4.3dB and a fast response speed measured to be 3.5 and 8.8 μs for raise and fall switching time, respectively.     

Coplanar Waveguide Fed Printed Antenna with Compact Size for Broadband Wireless Applications

A novel and simple coplanar waveguide fed compact antenna is introduced in this paper. The antenna structure combines the advantages of CPW with those of the broadband antenna and simplifies the structure of the antenna by reducing the number of metallization level to construct uni-planar antenna. Prototype of the proposed antenna have been constructed and studied experimentally. The measured results agrees well with the simulated prediction and shows a broad bandwidth of 6 GHz ranging from 3.5 GHz to 9.5 GHz with VSWR ≤2 (return loss ≤−10 dB), which is equivalent to 92.3% impedance bandwidth centered at 6.5 GHz. The proposed antenna shows stable radiation characteristics, gain and axial ratio of less than 1 dB over the whole operating bandwidth. Furthermore, an extensive parametric study was performed to realize the relationship between the resonance frequencies of the broadband antennas and different parameters which is helpful for advancement of the antenna design.     

基于双耦合器的全光纤不等带宽波长交错滤波器的设计

为提高波长交错滤波器(interleaver)带宽的利用 率,提出了基于一字型3×3和2×2光纤耦合器组成 全光纤马赫-曾德尔干涉仪(MZI)型不等带宽波长交错滤波器(interleaver)的设计方案。运 用光纤传输理论 和矩阵理论,得到滤波器输出谱的表达式;依据傅里叶级数的理论,优化选择器件的结构参 数;数值 模拟分析了器件的输出特性。结果表明:两个耦合器的耦合系数和光纤干涉臂长差取一些定 值时,器 件主要的两路输出带宽不等,它们的3dB带宽分别为31.5和 65.6GHz,满足不同传输速率10和40Gbit/s对带宽的要求,较等带宽interle aver有更高的利用率;通过分析器件结构参数对输出谱的影 响,发现器件具有一定的抗偏差能力;与普通的级联MZI型interleaver相比,新型器件的优 点是耦合 器少,在实际制作时可准确控制和检测耦合器的分光比,从而降低了制作难度。实验结果与 理论分析相吻合。     

基于平板光波导任意带宽比的新型非对称交错滤波器

为了提高目前光纤通信系统的10 Gbit/s和40 Gbit/s混合系统的传输效率,提出了一种新型的器件结构以实现基于平面光波导的不等带宽交错滤波器。该结构结合光学微环与马赫曾德尔干涉仪结构,通过控制相关关键参数,实现了任意带宽比的光学交错滤波器,给出了带宽比为12的非对称交错滤波器设计实例。仿真结果表明,设计的交错滤波器在信道间隔为100 GHz的系统中给传输速率为10 Gbit/s和40 Gbit/s的两个信道分别分配了32.85 GHz和67.15 GHz的带宽,从而解决了传输速率为40 Gbit/s的信道带宽不足的问题。在此基础上通过分析器件中各双模干涉仪的光功率分配比对输出谱带宽比的影响,给出了在相同信道间隔条件下不同带宽比的非对称交错滤波器的设计实例。     

Multilayer resonators and a bandpass filter fabricated from a novel low-temperature co-fired ceramic

The main objective of this study was to make components from a novel low-loss, low-temperature Co-fired ceramic (LTCC) dielectric, which was also compatible with a high-conductivity silver paste. The multilayer-component fabrication procedure is presented together with a composition for a tape-casting slurry, choice of conductor paste, and LTCC process parameters. A good Q factor, >100 at 2 GHz, using the novel material system has been achieved for λ/2 resonators operating in the frequency range 1.7–3.7 GHz. An excellent frequency response for a 2 GHz bandpass filter has also been achieved; the insertion losses in the passband were less than −2 dB (bandwidth 60 MHz) and the attenuation more than 25 dB in the stopband located 190 MHz higher.