Guided-wave optical wavelength-division multi/demultiplexer using high-silica channel waveguides

A guided-wave optical waveguide-division multi/demultiplexer for bidirectional transmission at (0.81 ?m, 1.2 ?m)/(0.89 ?m, 1.3 ?m) wavelengths has been realised using high-silica channel waveguides on silicon substrate. The multi/demultiplexer connected with graded-index multi-mode fibres shows a loss of 3.5?5 dB together with far-end and near-end crosstalk levels less than ?30 dB and ?50 dB, respectively.     

Wideband guided-wave periodic multi/demultiplexer with a ringcavity for optical FDM transmission systems

A guided-wave periodic multi/demultiplexer with a ring cavity for optical frequency-division-multiplexing (FDM) transmission systems is demonstrated. The frequency spacing is 5 GHz at the 1.55 μm wavelength region and the bandwidth is 1.8 times as wide as that of conventional periodic filters with simple Mach-Zehnder interferometer structure     

5 GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical FDM transmission systems

A 5GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical frequency-division-multiplexing (FDM) transmission systems is demonstrated. It is constructed with high-silica channel waveguides and thin-film heaters loaded on the waveguides for frequency tuning     

Multireflection optical multi/demultiplexer using interference filters

A multireflection multi/demultiplexer using interference filters is proposed. Light waves of different wavelengths are combined or separated while they propagate between two filter arrays. The insertion loss of the 6-channel demultiplexer was around 1dB.     

阵列波导光栅复用器优化设计的数值计算

阵列波导光栅(AWG)复用／解复用器的优化设计计算是集成光波导器件设计计算中的难点．文章应用AWG光信号传输特性和光栅方程，提出了AWG组成部分输入／输出波导、阵列波导、平板波导相关参数及阵列波导结构优化设计的数值计算方法，给出了具体的计算数值；该计算方法解决了AWG复用器优化设计计算的问题，为进一步建立AWG的计算机辅助设计提供了基础．     

Low-loss 10-GHz-spaced tandem multi/demultiplexer with more than1000 channels using a 1×5 interference multi/demultiplexer as aprimary filter

A very large channel-count low-loss optical multi/demultiplexer with more than 1000 channels is described. It was achieved by cascading a 1×5 flat-top interference multi/demultiplexer as a primary filter and five 10 GHz-spaced 1×288 arrayed-waveguide gratings as secondary filters in a tandem configuration     

基于慢光效应的解波分复用器的设计与研究

为了设计一种基于正方晶格光子晶体波导的三端口解波分复用器,利用光子晶体的光子带隙特性和光在光子晶体慢光波导中的传输特性,并采用平面波展开法及时域有限差分法对解波分复用器的特性进行了理论分析,数值计算了解复用器的空间和光谱分布特性。结果表明,调整波导中与波导紧邻的第1排柱子的位置,使三部分波导中传输的慢光频率发生改变,通过合理的结构设计,利用慢光模式传输的特点将不同频率的光从不同的输出端输出,可实现解复用的目的。     

Design and fabrication of ultra-small overlapped AWG demultiplexer based on /spl alpha/-Si nanowire waveguides

A novel layout for an ultra-compact arrayed-waveguide grating (AWG) demultiplexer is presented. The present layout has two overlapped free propagation regions, and is more compact than a conventional layout. Using /spl alpha/Si-on-SiO/sub 2/ nanowire waveguides, an ultra-small 4/spl times/4 AWG (about 40/spl times/50 /spl mu/m/sup 2/) with channel spacing of 11 nm is fabricated and characterised.     

1.5%-/spl Delta/ athermal arrayed-waveguide grating multi/demultiplexer with very low loss groove design

We describe a compact 1.5%-/spl Delta/ athermal silica-based 100-GHz-spacing 16-channel arrayed-waveguide grating (AWG) multi/demultiplexer with a modified groove design for a very low excess loss. We propose new approaches for modifying the shape of the grooves and the arrayed waveguides and optimize the shape modifications for 1.5%-/spl Delta/ waveguides. By employing this modified groove design, we greatly reduced the groove excess loss from 1.9 to 0.4 dB in the 1.5%-/spl Delta/ athermal AWG.     

Broad-passband-width optical filter for multi/demultiplexer using a diffraction grating and a retroreflector prism

The letter describes the experimental results of a novel optical filter for a multi/demultiplexer using a diffraction grating and a retroreflector prism. A broader passband width, which is proportional to the difference between the prism base length and the input fibre core diameter, is obtained. The minimum insertion loss is 2.2 dB.     

Ultrafast optical multi/demultiplexer utilising optical kerb effect in polarisation-maintaining single-mode fibres

An ultrafast time-domain optical multi/demultiplexer utilising the optical Kerr effect in two birefringent fibres concatenated with each fast axis crossed is proposed. Stable demultiplexing of an ultrashort 30 ps optical pulse train at 1.97 GHz from a gain-switched DFB LD has been successfully demonstrated using CW mode-locked Nd:YAG laser control pulses.     

A 4-wavelength optical multi/demultiplexer for WDM subscriber loop systems using analog baseband video transmission

This paper describes the design principles and performance of optical multi/demultiplexers (MUX/DEMUX's) in wavelength-division multiplexing (WDM) subscriber-loop systems over a 50- μm core diameter, graded-index (GI), multimode fiber, which employ analog baseband video transmission using laser diodes (LD's). In this WDM arrangement, requirements for MUX/DEMUX's are: 1) low insertion loss; 2) no signal degradation caused by optical interchannel crosstalk; 3) only a small amount of analog baseband signal degradation caused by the use of MUX/DEMUX; 4) a small size and simple structure capable of multiplexing three or four wavelengths; and 5) good stability. The newly developed 4-wavelength MUX/DEMUX satisfies the preceding requirements and is suitable for application to WDM subscriber-loop systems using analog baseband signals along with digital signals.     

Hybrid optical circulator using garnet-quartz composite embedded in planar waveguides

A novel hybrid configuration of optical circulator is presented. A Garnet-Quartz composite (GQC), which is comprised of four quarter-wave plates and Faraday rotator, is embedded into a groove formed across the branching waveguides pair of Mach-Zehnder interferometer. Optical path difference of the pair is 0 rad for forward path, whereas /spl pi/ for backward path with the GQC, realizing nonreciprocal operation. The forward-to-reverse isolation of 16.2-29.8 dB and the insertion loss of 8.8-9.4 dB are obtained.     

基于液体选择填充光子晶体光纤的波分解复用器研究

设计了一种基于液体选择填充三芯光子晶体光纤的1.31/1.55um波分解复用器。中间为缺失一个空气孔的普通二氧化硅纤芯,左右两纤芯填充了不同折射率的液体材料。根据光纤的消逝场耦合的模式理论,不对称相邻波导存在波长相关耦合。不同填充折射率的两纤芯与中间纤芯分别耦合,构成两个不同响应波长的光滤波器。通过选择合适光纤长度,可实现不同波长光的分离。采用全矢量有限元法分析了光纤的传输特性,讨论了填充不同折射率液体时波导间的模式耦合,得到了其匹配波长与耦合长度。基于光束传播法仿真发现,长度为4.88 mm的光纤能实现1.31/1.55 um波长光的解复用。     

Electro-optical modulators using novel buried waveguides inGaInAsP/InP material

Losses as low as 0.4±0.2 dB/cm and electro-optical modulation efficiencies as high as 5°/V/mm have been obtained in single mode waveguides employing a novel buried structure in GaInAsP/InP grown by LPMOCVD and processed by selective chemical etching. Such modulators are potentially excellent candidates for integrated optoelectronics     

Ultrafast time-division demultiplexer based on electrooptic on/offgates

Electrooptic on/off gate-based demultiplexers for high-bit-rate optical transmission systems are reported. The electrooptic demultiplexing of a TDM 49.6 Gb/s fixed pattern data stream is demonstrated, using two cascaded Ti:LiNbO₃ electroabsorptive multi-quantum-well intensity modulators driven at 6.2 GHz. Error-free 10 Gb/s demultiplexing to 5 Gb/s is achieved using cascaded Mach-Zehnder (MZ) modulators driven at 1.25 GHz. The power penalty due to the interchannel crosstalk is 0.3 dB at the bit error rate of 10^-9     

High-Δn silica-on-silicon channel waveguides based on sol-gelgermanophosphosilicate glass

A process for fabrication of high-Δn silica-on-silicon channel waveguides by spin-coating and rapid thermal annealing of sol-gel germanophosphosilicate glass is described. A recipe for the preparation of stable sols and a parameter range for deposition of crack-free films are given. Low and spectrally flat insertion loss is demonstrated for singlemode guides with a Δn of 1.5×10^-2     

High-performance FIR filter design based on sharing multiplication

Finite impulse response (FIR) filtering can be expressed as multiplications of vectors by scalars. We present high-speed designs for FIR filters based on a computation sharing multiplier which specifically targets computation re-use in vector-scalar products. The performance of the proposed implementation is compared with implementations based on carry-save and Wallace tree multipliers in 0.35-/spl mu/m technology. We show that sharing multiplier scheme improves speed by approximately 52 and 33% with respect to the FIR filter implementations based on the carry-save multiplier and Wallace tree multiplier, respectively. In addition, sharing multiplier scheme has a relatively small power delay product than other multiplier schemes. Using voltage scaling, power consumption of the FIR filter based on computation sharing multiplier can be reduced to 41% of the FIR filter based on the Wallace tree multiplier for the same frequency of operation.     

基于嵌入式的GUI设计与实现

随着信息技术的快速发展,基于嵌入式GUI的人机界面显示技术日渐成熟从而被应用到更多的行业和领域,其在医疗行业也得到了推广,并成为了医疗器械数字化、智能化建设的重点.本文研究了一种基于GUI Designer人机界面系统,通过硬件电路设计及软件系统进行实现;该系统设计简便,适用性强,可以广泛应用于医疗器械行业及其他不同场...