AWG波分复用器的多频调制色散特性

通过对弯曲阵列波导的优化设计 ,讨论了阵列波导光栅 (AWG)作波分复用器传输多频线性调制信号时的色散特性 ,得到其传输功率与波长的关系。分析表明 :对于优化弯曲波导 ,脉冲展宽波长Δλ≤ 0 .5nm ,插入损耗为 6± 1dB     

W波段行波管金刚石窗的模拟优化与性能测试

本文主要研究了使用金刚石窗片的W波段标准盒形窗,利用三维模拟软件CST微波工作室进行了计算与优化,设计出适合W波段行波管使用的输能窗。冷测结果显示,在75~110 GHz范围内驻波系数均在1.47以下。     

有限元法的脊位于窄边的脊波导特征值分析

提出用有限元方法分析位于窄边的脊波导主模的截止波长和场结构图以及单模带宽特性，推导出用有限元法计算相关参数的计算公式。编程计算了双脊、单脊和不对称脊波导的特征值，求解了三种脊位于窄边的脊波导的传输特性，并给出了截止波长和单模带宽曲线以及场结构变化。     

平面阵列光学波导模式特性及其光强传输分析

分析了平面阵列波导的模式特性.其导波模式为周期性调幅的平面波(Bloch波).阵列波导输入/输出波导结构是影响其传输特性的重要因素.采用扇形过渡波导结构以提高阵列波导输入/输出端口芯区宽度与波导周期宽度的比值,可降低阵列波导光强的传递损耗.并可改善布里渊区入射/出射波的损耗非均匀性.采用低折射率差的波导芯区/包层结构可降低波导对光波的限制,提高光强的传输效率     

缺陷型内包层双包层光纤吸收效率研究

缺陷型内包层双包层光纤由于其特殊的内包层横截面结构,对于光波的吸收效率要比理想圆型内包层双包层光纤提高许多.由于射线法在分析光波在光纤中的场分布、传播功率等情况时有其局限性,因此,文章改用波动理论对缺陷型内包层双包层光纤进行分析,试图找出不同类型的缺陷型内包层双包层光纤单位距离内吸收效率的差异.     

阵列波导光栅薄膜的制备及性能

以一种特定成分的有机硅为原料,采用溶胶-凝胶法,在硅基片上制备出用于光波导器件的薄膜.通过折射率和厚度测试及XPS成分测试验证了此薄膜具有较好的均匀性、厚度和光学特性,满足光波导器件的要求.分析了溶胶-凝胶法中常见的龟裂现象的原因以及采预防方法.利用这种薄膜结合微电子加工工艺制备出光波导器件阵列波导光栅.     

异形孔零件的线切割编程与加工

通过对典型零件的加工工艺分析，介绍了用北京迪蒙卡特线切割机床加工锥度、上下异形类零件的程序编制规则和方法，该方法相比TurboCAD软件自动编程操作简单快捷，编程者更易掌握。     

Design and analysis of implantable CPW fed bowtie antenna for ISM band applications

A novel implantable coplanar waveguide (CPW) fed crossed bowtie antenna is proposed for short-range biomedical applications. The antenna is designed to resonate at 2.45 GHz, one of the industrial-scientific-medical (ISM) bands. It is investigated by use of the method of moments design equations and its simulation software (IE3D version 15). The size of the antenna is 371.8 mm³ (26 mm × 22 mm × 0.65 mm). The simulated and analyzed return losses are −23 and −25 dB at the resonant frequency of 2.45 GHz. We have analyzed some more performances of the proposed antenna and the results show that the proposed antenna is a perfect candidate for implantation. The proposed antenna has substantial merits like low profile, miniaturization, lower return loss and better impedance matching with high gain over other implanted antennas.     

Alkaline aluminum phosphate glasses for thermal ion-exchanged optical waveguide

Alkaline aluminum phosphate glasses (NMAP) with excellent chemical durability for thermal ion-exchanged optical waveguide have been designed and investigated. The transition temperature Tg (470 °C) is higher than the ion-exchange temperature (390 °C), which is favorable to sustain the stability of the glass structure for planar waveguide fabrication. The effective diffusion coefficient D_e of K⁺–Na⁺ ion exchange in NMAP glasses is 0.110 μm²/min, indicating that ion exchange can be achieved efficiently in the optical glasses. Single-mode channel waveguide has been fabricated on Er³⁺/Yb³⁺ doped NMAP glass substrate by standard micro-fabrication and K⁺–Na⁺ ion exchange. The mode field diameter is 9.6 μm in the horizontal direction and 6.0 μm in the vertical direction, respectively, indicating an excellent overlap with a standard single-mode fiber. Judd–Ofelt intensity parameter Ω₂ is 5.47 × 10⁻²⁰ cm², implying a strong asymmetrical and covalent environment around Er³⁺ in the optical glasses. The full width at half maximum and maximum stimulated emission cross section of the ⁴I_13/2 → ⁴I_15/2 are 30 nm and 6.80 × 10⁻²¹ cm², respectively, demonstrating that the phosphate glasses are potential glass candidates in developing compact optoelectronic devices. Pr³⁺, Tm³⁺ and Ho³⁺ doped NMAP glasses are promising candidates to fabricate waveguide amplifiers and lasers operating at special telecommunication windows.     

220 GHz折叠波导慢波结构的有损参数化模型

建立了自洽的考虑波导璧损耗的折叠波导等效电路模型,用来计算该慢波结构周期TE10模式中各次空间谐波的相速度,耦合阻抗和线衰减系数.分析结果将会用到220 GHz折叠波导返波管一维束波互作用模型的计算中.当微波频率上升到太赫兹波段时,粗糙波导表面电流导致的壁损将不能再忽略不计.进一步研究表明,起振电流和输出功率水平将和损耗特性的计算密切相关.从原有模型发展而来的有损电路模型可以给出更准确损耗估计.建立了折叠波导慢波线三维谐振腔模型来验证本文的等效电路理论,有较好的吻合.采用了该理论导出参数的一维束波互作用模型和三维数值PIC方法同样有很好的一致性.