采用角谱色散补偿法的宽带三倍频方案分析

针对线性啁啾的宽频带激光,分析了采用角谱色散(ASD)方法实现Ⅰ/Ⅱ类角度失谐的KDP晶体三倍频方案,讨论了光栅角色散、入射基频光的光强、带宽以及晶体厚度对三倍频转换效率、脉冲波形和光谱分布的影响,并对采用角谱色散补偿法的宽带三倍频方案参数进行了优化.研究结果表明,采用ASD方法,不仅能有效地提高带宽较宽条件下三倍频光的转换效率,而且还可以使三倍频光脉宽和带宽明显变宽、脉冲波形和光谱分布变光滑.经方案优化后,当入射基频光带宽11.2nm、光强2-6GW/cm2时的三倍频光转换效率可达到60%左右,比不采用ASD时的三倍频光转换效率提高了40%左右.     

32信道聚合物阵列波导光栅的制作与测试

对一个32通道的聚合物阵列波导光栅进行了研究和制作.经过旋涂、光刻、反应离子刻蚀等工艺过程,利用A1掩膜技术和回融技术进行了器件的制作.实验结果表明,回融技术使样本的波导表面的均方根粗糙度降低了约0.02μm.测试结果表明,器件的结构指标与理论设计值基本相符,并且波导在C波段上实现了单模传输.器件的插入损耗约为35dB,相邻通道串扰小于-20dB,很好地实现了波分复用功能.     

三阶聚合物波导布拉格光栅的设计与制备

利用紫外固化聚合物材料ZPU46和ZPU44分别作为 芯层和包层材料,设计并制备了中心波长在 1550nm附近的三阶聚合物波导布拉格光栅(WBG )滤波器。采用接触式光刻和反应离子刻蚀(RIE)等传统微加工工艺, 在高为4μm的单模矩形波导表面制备周期为1.6μm、高为 680nm的皱褶型光栅结构。实验测得截面 尺寸为4μm×4.2μm和5μm×4.2μm) 的三阶聚合物WBG的谐振波长分 别为1549550.5nm,边模抑制比分别为 19dB,3dB带宽分别为0.4nm和0.6nm,插入损耗为－7d B,与理论设计结果符合较好。     

（英）钡铁氧体薄膜自偏置毫米波环行器设计与制备

基于厚度为10 μm的钡铁氧体薄膜设计,制备了共面波导结构的毫米波薄膜环行器.这种薄膜环行器不需要外加磁体,在34 GHz和37.6 GHz显示出环行特性,其非互易效应大于15 dB.结果表明,采用共面波导结构可以实现薄膜环行器.这种薄膜环行器具有和单片微波集成电路集成的潜在应用.     

Micro-indentation relaxation measurements in polymer thin films

A micro-indenter consisting of a piezo-electric driven flat cylindrical punch has been used to measure the dynamic mechanical properties of polystyrene films as thin as 50 μm. The measured viscoelastic response was sensitive to the bonding of the polystyrene to an underlying silicon substrate for films which were thinner than one indenter diameter. The instrument therefore was shown to have practical use in measuring the dynamic mechanical response of polymer films, and the strength of bonding between disparate materials.     

High CMRR wide bandwidth instrumentation amplifier using current controlled conveyors

A novel instrumentation amplifier using only current controlled conveyors (CCCIIs) is proposed. The new circuit with no resistors offers a wide bandwidth, a high CMRR, electronically adjustable gain and a good dynamic range. The proposed circuit also provides simultaneously a high impedance output current. The circuit is also analysed for the non-idealities of conveyors. RSPICE simulation results are included to support the proposed theory.     

一种用于薄膜热容测量的微热量计的设计与制作

目前已发现并证实薄膜的热导率和热扩散率存在着尺寸效应。本文为了研究薄膜的另一个热学性质比热是否也具有尺寸效应 ,提出了一种用于薄膜热容测量的新方法 ,其相应的实验器件为一悬膜结构。从理论上阐述了其测量原理 ,结合ANSYS热学模拟设计并利用微机械加工技术制作出SiO2 悬膜结构 ,悬膜由两个悬臂支撑 ,在悬膜上制作了Pt薄膜电阻同时用于加热和测温。这种结构加快了样品、悬膜和加热 /测温电阻之间的热传递 ,减小了悬膜的热损失 ,提高了测量精度。     

一种用于薄膜热容测量的微热量计的设计与制作

目前已发现并证实薄膜的热导率和热扩散率存在着尺寸效应。本文为了研究薄膜的另一个热学性质比热是否也具有尺寸效应,提出了一种用于薄膜热容测量的新方法,其相应的实验器件为一悬膜结构。从理论上阐述了其测量原理,结合ANSYS热学模拟设计并利用微机械加工技术制作出SiO2悬膜结构,悬膜由两个悬臂支撑,在悬膜上制作了Pt薄膜电阻同时用于加热和测温。这种结构加快了样品、悬膜和加热/测温电阻之间的热传递,减小了悬膜的热损失,提高了测量精度。     

Integrated multichannel OADMs using polymer Bragg grating MZIs

We report the first fabrication of Bragg-grating-based multichannel optical add/drop multiplexers (OADMs) in planar polymers. The filters were designed by cascading multiple stages of single-channel multi-/demultiplexers. Each stage consists of a Mach-Zehnder interferometer (MZI) with a Bragg grating across its arms. The 3-dB couplers in each MZI are multimode interference (MMI) couplers. We fabricated the first tapered MMI couplers, which provide compactness. The gratings were printed photochemically, achieving index differences as high as 10^-3 and reflectivities as large as 33 dB. The 3-dB bandwidth is about 0.2 nm. Apodization was used to reduce sidelobes in the reflection spectrum. Four-channel OADMs were produced and exhibited the proper 400-GHz channel separation and ITU grid wavelength alignment, as well as excellent channel isolation and uniform channel response     

Ultra-short pulsed laser deposition and patterning of SiC thin films for MEMS fabrication

A Ti:Sapphire (IR 800-nm) femtosecond (fs) pulsed laser was used to ablate a sputtering grade of silicon carbide (SiC) in an ultra-high vacuum chamber. The laser-induced plasma species were then driven and grown to form 3C-SiC films of about 1 μm thick on single crystal silicon wafers at 20 °C (room temperature) and 500 °C. Scanning electron microscopy, atomic force microscopy, X-ray photoelectron microscopy, X-ray diffraction and nanoindentation were used to characterize the structure, composition, thickness and properties of the SiC films. Results of the femtosecond-pulse laser deposited (fs-PLD) films were compared with those obtained by atmospheric pressure chemical vapor deposition (APCVD) and nanosecond-pulse laser (excimer laser at 248-nm) deposition (ns-PLD). The distinctive features of fs-PLD films are their extremely smooth surfaces, stoichiometry, amorphous structure and low defect density compared to APCVD films, along with better film quality and higher growth rates than ns-PLD films. In addition to film growth studies, a SiC microgripper (to grab 20-μm-sized objects) was micromachined by use of the fs-pulsed laser to demonstrate the utility of ultra-short PLD in SiC-device fabrication.     

Spray deposition of Polyethylenimine thin films for the fabrication of fully-sprayed organic photodiodes

In the last years, a big effort has been put into the investigation of the scalability of deposition processes for organic optoelectronics to achieve large-scale and cost-effective fabrication of functional devices. One of the most prominent techniques that promises to obtain an easy-to-scale production is spray-deposition; however, so far, the feasibility of entirely spray-deposited optoelectronic devices has not yet been demonstrated. To fulfill this goal, in this work we investigate the spray-coating of Polyethylenimine (PEI) and the effect of the process parameters on the film characteristics, in terms of thickness, work-function and roughness. The achievement of thin layers of PEI (∼10 nm) with full coverage is the last step towards the realization of lithography-free and vacuum-free organic electronic devices. For the first time, we show the fabrication of fully-sprayed organic photodiodes (OPDs), initially on patterned Indium-Tin Oxide, and subsequently on bare glass. The resulting photodiodes yield peak EQE above 65% and dark currents lower than 10–4 mA/cm² at a reverse bias of −4 V. Moreover, both the cathode and anode electrode of the OPDs fabricated with the described process-flow are semi-transparent, granting the simultaneous collection of two different light signals from the top and the bottom side.     

MOS structure fabrication by thermal oxidation of multilayer metal thin films

A novel approach for the fabrication of a metal oxide semiconductor(MOS) structure was reported.The process comprises electrochemical deposition of aluminum and zinc layers on a base of nickel-chromium alloy. This two-layer structure was thermally oxidized at 400℃for 40 min to produce thin layers of aluminum oxide as an insulator and zinc oxide as a semiconductor on a metallic substrate.Using deposition parameters,device dimensions and SEM micrographs of the layers,the device parameters were calculated.T...     

MOS structure fabrication by thermal oxidation of multilayer metal thin films

A novel approach for the fabrication of a metal oxide semiconductor(MOS) structure was reported.The process comprises electrochemical deposition of aluminum and zinc layers on a base of nickel-chromium alloy. This two-layer structure was thermally oxidized at 400℃for 40 min to produce thin layers of aluminum oxide as an insulator and zinc oxide as a semiconductor on a metallic substrate.Using deposition parameters,device dimensions and SEM micrographs of the layers,the device parameters were calculated.The resultant MOS structure was characterized by a C-V curve method.From this curve,the device maximum capacitance and threshold voltage were estimated to be about 0.74 nF and -2.9 V,respectively,which are in the order of model-based calculations.     

Fiber Bragg grating fabrication for dispersion slope compensation

Group-delay dispersion slope causes signal deterioration in long-distance high-data-rate communication systems. We report the fabrication of high-quality apodized and chirped fiber gratings with dispersion slopes as high as -1800 ps/nm/sup -2/ over a 0.7-mn bandwidth-sufficient to compensate for the dispersion slope of >25000-km length of standard fiber at a wavelength of 1550 nm. We believe this is the first time that fiber Bragg gratings have been specifically designed and fabricated for dispersion slope compensation. The fabrication technique uses a standard unchirped phase mask and two scans of the inscribing UV beam.     

Modified Talbot interferometer for fabrication of fiber-opticgrating filter over a wide range of Bragg wavelength and bandwidth usinga single phase mask

A technique involving a compact apparatus that combines the phase mask and two-beam interferometric techniques is presented. It involves the use of a phase mask to diffract the ultraviolet (UV) beam and a cylindrical lens combined with a pair of mirrors to produce two symmetric virtual line sources of UV light. Bragg wavelength and bandwidth of the fiber gratings can be controlled with a simple translation of the fiber and/or the phase mask. Using a 40-mw continuous-wave frequency-doubled argon-ion laser at 244 mm and a single phase mask, a series of chirped fiber gratings with the Bragg wavelength in a wide range around 600 nm and 1300 nm are fabricated in hydrogen-loaded ordinary fibers     

ISFET's using inorganic gate thin films

The characteristics of various types of ISFET's using inorganic gate films are described. The pH and pNa selectivities are investigated for SiO2, Si3N4, Al2O3, alumino-silicate, and sodium-aluminosilicate gate dielectrics. The transient response and device stability are also studied for different values of solution pH. The Al2O3gate shows a nearly ideal pH response, excellent stability, and selectivity to other cations. On the other hand, the Si3N4gate is also a good pH sensor, but it is proved by the studies of SiO2and SiOxNyfilms that the oxygen content in its surface degrades its properties as a pH sensor. Sodium-alumino-silicate, which is generally known as a material for pNa selective glass electrodes, is utilized as a gate film for the pNa ISFET. The pNa selectivity of this device is comparable to that of the conventional glass electrode. The alumino-silicate gate has also a pNa selectivity, but it is inferior to the sodium-alumino-silicate gate.     

A novel fabrication approach for an athermal arrayed-waveguide grating

A novel method for fabricating an athermal AWG is proposed, using a unique apparatus for ITU-T center wavelength adjustment and optical coupling of two cut-parts. UV adhesive or sticky gel is applied into the gap between the cut-elements and the alignment base substrate by capillary infiltration. The spectrum profiles are almost the same as those of the original chip state, and no deterioration is observed resulting from athermalization. Flat-top athermal AWG modules of 100 GHz×40 ch are fabricated. Over a temperature range of-40 to 85℃, the center wavelength shift is±22 pm, and the insertion loss change is less than ±0.11 dB.     

无热阵列波导光栅的新颖制作方法

提出了一种制作无热AWG的新颖方法,采用了专利设计的ITU-T中心波长调节装置、简单的方法来耦合被切开两部分、以及毛细渗透的点胶方式。波长调节精度达到1pm。这种无热实现方案没有带来任何光谱恶化,其光谱几乎同原始芯片一样。这种40通道100GHz通道间隔平顶型无热AWG,在-40 to 85℃范围内,中心波长漂移±22pm,插损变化小于±0.11dB。     

17×17 波谱响应平坦化聚合物阵列波导光栅工艺效果分析

Based on transmission theory, a 17×17 polymer arrayed waveguide grating(AWG) multiplexer parameter optimization is performed, and the influence of the fabrication results on the transmission characteristics are analyzed. In this paper, we mainly discuss three of the main errors in the fabrication of polymer AWG devices. One is n1, which is caused by the tuning of the core refractive index n1, the second is b, which results from the rotating-coating of the core thickness b, and the other is the non-ideal core cross-section, which is caused by steam redissolution. The effects of the above fabrication errors on the transmission characteristics of the AWG device are investigated, and compensation techniques are proposed. By comparing the theoretical simulation and experimental results, the shift in the transmission spectrum is reduced by 0.028 nm, the 3 dB bandwidth is increased by about 0.036 nm, the insertion loss is reduced by about 3 dB for the central channel and 4.5 dB for the edge channels, and the crosstalk is reduced by 1.5 dB.