Topology and analysis of an N-stage cascaded polymer eight-port microring optical router with 7N channel wavelengths

Eight-port optical routers are widely used in cluster-mesh photonic networks-on-chip(No C). By using 24 groups of cross-coupling two-ring resonators, a 1-stage 8-port polymer optical router is proposed, which can optically route 7 channel wavelength data streams along definite path in two-dimensional(2D) plane. Under the selected 7 channel wavelengths, the insertion losses along all routing paths are within 0.02-0.58 d B, the maximum crosstalk of all routing operations is less than-39 d B, and the device footprint size is about 0.79 mm2. Then, a universal novel structure and routing scheme of N-stage cascaded 8-port optical router are presented, which contains 7N channel wavelengths. Because of the good scalability in wavelength, this device shows potential application of wideband signal routing in optical No C.     

Strict non-blocking four-port optical router for mesh photonic network-on-chip

We report a strict non-blocking four-port optical router that is used for a mesh photonic network-on-chip on a silicon-on-insulator platform. The router consists of eight silicon microring switches that are tuned by the thermo-optic effect. For each tested rousting state, the signal-to-noise ratio of the optical router is larger than 13.8 dB at the working wavelength. The routing functionality of the device is verified. We perform 40 Gbps nonreturn to zero code data transmission on its 12 optical links. Meanwhile, data transmission using wavelength division multiplexing on eight channels in the C band (from 1525 to 1565 nm) has been adopted to increase the communication capacity. The optical router’s average energy efficiency is 25.52 fJ/bit. The rising times (10% to 90%) of the eight optical switch elements are less than 10 µs and the falling times (90%–10%) are less than 20 µs.     

Non-blocking four-port optical router based on thermo- optic silicon microrings

By using silicon-on-insulator(SOI) platform, 12 channel waveguides, and four parallel-coupling one-microring resonator routing elements, a non-blocking four-port optical router is proposed. Structure design and optimization are performed on the routing elements at 1 550 nm. At drop state with a power consumption of 0 m W, the insertion loss of the drop port is less than 1.12 d B, and the crosstalk between the two output ports is less than-28 d B; at through state with a power consumption of 22 m W, the insertion loss of the through port is less than 0.45 d B, and the crosstalk between the two output ports is below-21 d B. Routing topology and function are demonstrated for the four-port optical router. The router can work at nine non-blocking routing states using the thermo-optic(TO) effect of silicon for tuning the resonance of each switching element. Detailed characterizations are presented, including output spectrum, insertion loss, and crosstalk. According to the analysis on all the data links of the router, the insertion loss is within the range of 0.13—3.36 d B, and the crosstalk is less than-19.46 d B. The router can meet the need of large-scale optical network-on-chip(ONo C).     

Highly-scalable load-balanced router with optical switch fabric

A novel load-balanced optical packet router architecture is proposed and demonstrated. High scalability and reduced complexity are achieved by using optical switch fabrics, FPGA-based 10 Gbit/s packet processors and no centralised scheduler.     

Optimum design of a polymer electro-optic microring resonator switch

Novel transfer functions are presented for a polymer electro-optic microring resonator switches. The resonating process of the light in the microring is simulated using the formulas. Then the optimization of the structural parameters is performed, and the characteristics are analyzed, such as the resonance time, output spectrum, operation voltage, insertion loss and crosstalk were analyzed. The simulation results show that the designed device exhibits favorable switching functions.     

Digitally tunable channel dropping filter/equalizer based onwaveguide grating router and optical amplifier integration

We demonstrate a novel and powerful device that permits individual and simultaneous control of all the wavelength channels in a WDM system. The device is based on the monolithic integration of two identical waveguide grating routers with semiconductor optical amplifiers. By biasing appropriately the individual amplifier, each WDM channel can be amplified, detected or modulated. The device exhibits a channel bandwidth of 60 GHz, a channel spacing of 195 GHz and a crosstalk of -19 dB     

IP router using optical address recognition with second-harmonic generator

A novel optical header address recognition using a second-harmonic generator cascaded with optical correlator is proposed as a cost-effective way of realising routing in optical networks. The second-harmonic generator is used for minimising optical loss due to wavelength mismatch, while the optical correlator performs address recognition.     

Study of a novel pressure sensor based on optical microring resonator

We propose a novel pressure sensor based on the combination of the ring resonator with two straight waveguides and a two-end fixed beam. The principle of this device is acquiring the system static pressure by monitoring the changes in the transmission wavelength shift of the ring resonator with double waveguides. The numerical results show that the sensitivity of the system is up to 49.3 pm/kPa while the pressure range is 0--300 kPa. The thickness of the fixed beam is an important factor which impacts the sensitivity of the system. This device can provide support for fabricating high sensitivity and low cost micro pressure sensors.     

Box-like spectral response of a series-coupled microring resonant filter in a parallel channel

Inthelast decades ,microring resonator( MRR) wave-lengthfilters are developed rapidly because of their po-tential applications in wavelength division multiplexing( WDM) communicationsystems andtheir excellent fea-tures includingfunctionality,compactness a…     

An optical router with multistage management functions for asynchronous optical packet switching network

An optical router with multistage distributed management features for the asynchronous optical packet switching (OPS) network is presented, which can improve switching capacity and all-optical scalability. A compact recycling-fiber-delay-line (Rec-FDL) based collision resolution mechanism is proposed to resolve the contentions for asynchronous and variable length optical packets. The analysis models of stabilities, packet loss rates (PLR) and average packet waiting latencies (PWL) for the router are developed based on the timer based optical packet assembly algorithm. The simulation shows that PLR and PWL for a 400-byte optical packet transmitted in the 32 wavelengths dense wavelength division multiplexing (DWDM) system equal to 3.48 × 10⁻⁴ and 0.072 ns, respectively. The non-blocking switching can be realized for the packets with lengths less than the buffer granularity of the Rec-FDL, and the optimized performance for the proposed router can be obtained through properly selecting of the system parameters.     

Electrically pumped InGaAsP-InP microring optical amplifiers and lasers with surface passivation

Vertically coupled electrically pumped InGaAsP microring optical amplifiers providing gain at 1550 nm are demonstrated. The microrings provide up to 10 dB of gain at the through-port in pulsed mode. The bias current is used to control the loss in the ring and, hence, the region of operation (under-coupled, critically coupled, transparency, and gain). Sulfur passivation is used to reduce carrier loss due to surface recombination in the active region. The amplifiers are designed for application in cascaded microring optical logic gates in photonic logic circuits.     

Research on router device of OAM optical communication

With the development of orbital angular momentum (OAM) based optical communication technology,OAM router played an important role in improving the flexibility and practicability of OAM communication system.In recent years,the research on multifunctional OAM router had also been developed rapidly.Based on this,the research results on the OAM router had been summarized and reviewed,in which the principles,research methods,advantages and disadvantages of six types of OAM router,with the functions of switching,multicast,filtering,adding/extraction,and jumping and mode dividing respectively,had been discussed and summarized in details.Meanwhile,the future developing trend of the OAM router has also been prospected and discussed in the end.     

相干光OFDM系统中MMSE信道估计研究

信道估计作为相干光正交频分复用(CO-OFDM)的 一种关键技术对系统的性能有着十分重要的影响。本文重点对系统信道估计的实现进行了数 学 分析,搭建起了CO-OFDM系统仿真平台,并在此平台上将提出的最小均方误差(MMSE)及其改进算法应用到CO- OFDM系统中进行信道估计。结果表明,MMSE及其改进算法能够很 好地提高CO-OFDM 系统的传输性能,在误码率(BER)为10－3时,与最小 二乘(LS)算法相比有约2dB的光信噪比(OSNR)增益,且改进型MMSE算 法的复杂度要比MMSE算法低2个数量级。     

工艺公差对聚合物竖直耦合型微环谐振器性能的影响

本文根据波导耦合模理论,分析了工艺公差对聚合物竖直耦合型微环谐振器性能的影响。分析结果表明,工艺公差将引起谐振器传输光谱的漂移和光谱形状的改变。为了实现谐振器正常的滤波功能,我们对微环谐振器工艺公差的累积和补偿效应进行了讨论。     

Wavelength trimming of a microring resonator filter by means of aUV sensitive polymer overlay

Trimming of the resonant wavelength of a vertically coupled glass microring resonator channel dropping filter with a photo-induced refractive index change in a dip coated polymer overlay is reported. In this letter, the glass microring resonator has a radius of 19 μm, a free-spectral range of 10 nm, and a Q value of 800. The maximum wavelength shift observed is 9 nm, which is yielded through an absolute bulk index change in the polymer of 0.044. Trimming is a continuous function of exposure time and dose     

Optimization design of optical waveguide in Mach-Zehnder electro-optical polymer modulator

In order to reduce transmission loss of the optical waveguide in Mach-Zehnder (M-Z) electro-optical (EO) polymer modulator,the basic iterative formula of semi-vector finite-difference beam propagation method (FD-BPM) is obtained from the scalar wave equation. The transition waveguide is combined with S-type bend branch waveguide for the M-Z EO modulator in the branch waveguide. The effects of structure parameters such as ridge width,length of the branch waveguide and interferometer spacing on the transmission loss are systematically studied by using the semi-vector FD-BPM method. The structure is optimized as an S-sine bend branch waveguide,with rib width w=7μm,length of branch waveguide L=1200μm and interferometer spacing G=22 μm. The results show that the optimized structure can reduce transmission loss to 0.083 dB,which have a certain reference value to the design of optical waveguide in M-Z polymer modulator.     

三种WDM光网络信道预测算法的比较

分别介绍了三种避免冲突的波分复用星形光网络调度算法,并对这三种WDM光网络信道预测算法作了全面的分析,最后在统一环境下做了仿真和比较.结果显示其中一种算法与其它两种算法相比,不仅提高了信道利用和网络吞吐量,而且减少了数据包的平均等待时间.     

双波长钛氧磷酸钾内腔光学参量振荡激光器

为实现1.06 μm波长激光向人眼安全1.57 μm激光的能量转移,同时在输出光束中保留原1.06 μm波长的泵浦光,以得到双波长激光的混合输出。本文从光参量振荡器(OPO)的基本原理出发,对磷酸氧钛钾(KTP)晶体的光学参量振荡(OPO)获得重频双波长激光输出的过程进行了理论分析和实验研究。采用内腔OPO(IOPO),工作在重频20 Hz下,获得了1.57 μm和1.06 μm双波长激光混合输出能量大于38 mJ,其中1.57 μm波长信号光20 mJ,脉宽5 ns;1.06 μm泵浦光18 mJ,脉宽6 ns,并且波形未出现外腔OPO所观察到的中央凹陷,实验结果与理论分析相吻合。     

Dispersion in a low-loss multimode fibre measured at three wavelengths

Short pulses from mode-locked lasers (neodynium/yttrium-iron-garnet and krypton) were used to measure mode and material dispersion in 20 m of a multimode fibre at 1060, 647 and 568 nm. Uniform illumination of the cone of acceptance at the input caused a 200 ps pulse to broaden to 400 ps.