硅基二氧化硅波导和SOI脊型波导应力双折射研究

采用有限元方法分析了硅基二氧化硅波导和SOI（Silicon on Insulator）脊型波导内部残留热应力引起的双折射.对于硅基二氧化硅波导,应力双折射系数的数量级为10－4,对于上包层为空气的SOI脊型波导,该系数的数量级为10－5,对于上包层为SiO2的SOI脊型波导,该系数的数量级为10－3,可见在硅基二氧化硅波导和上包层为SiO2的SOI脊型波导中产生了大的应力双折射,而在上包层为空气的SOI脊型波导中应力双折射较小.     

硅基二氧化硅光波导器件偏振特性的理论分析

从理论上分析了硅基二氧化硅光波导器件的芯区尺寸、相对折射率差、内应力和弯曲径对器件偏振特性的影响,得出结论：小折射率差的正方形波导的双折射系数小;内应力对双折射的影响比几何参数大;弯曲半径较小时,双折射系数较大,弯曲损耗也较大。     

硅基波导慢光器件及其应用

硅基波导慢光器件是构建全光智能互连和实时高速测控等下一代信息技术的关键器件,在光通信和光信息处理等诸多领域具有显著的技术优势和巨大的应用潜力.随着器件结构的不断创新以及微电子制造技术的不断升级换代,硅基波导慢光器件愈来愈走向实用化.文章介绍了慢光的基本原理,概述了当前国内外硅基波导慢光器件的研究进展,着重分析了基于微环谐振腔的硅基波导慢光器件,并指出了它在具体应用领域中的发展前景.     

硅基混合表面等离子体纳米光波导及集成器件

总结并展望了硅基混合表面等离子体纳米光波导及集成器件方面的理论和实验研究工作。首先介绍了几种硅基混合表面等离子体纳米光波导结构,其尺寸可小至100 nm以下,而传播长度达100μm量级;其次介绍了基于硅基混合表面等离子体纳米光波导的功分器、偏振分束器和谐振器等集成器件,其尺寸为亚微米量级;最后探讨了硅基混合表面等离子体纳米光波导与硅纳米线光波导的耦合及对其进行增益补偿。     

掺Bi钇铁石榴石薄膜光波导的线性双折射及消除方法

分析了光的线性双折射对磁光波导ＴＥ－ＴＭ模式转换，法拉第旋转，波导光隔离器隔离比及插入损耗的影响。研究了掺Ｂｉ钇铁石榴石薄膜光波导中的形状线性双折射，应力感生线性双折射及生长感生线性双折射的来源，特性和消除方法。     

硅基二氧化硅阵列波导光栅制作工艺的研究

硅基二氧化硅阵列波导光栅是集成化波分复用光网络中的核心器件之一.对其制作工艺的研究对提高器件的性能具有重大意义.提出一种在波导上包层使用硼锗共掺高温退火的工艺方法,成功实现阵列波导间空隙的填充,并将阵列波导光栅的插入损耗成功降低约2 dB.相对于传统的硼磷硅玻璃工艺,此方法避免了剧毒气体磷烷的使用,工艺简便安全,同时降...     

梯形截面硅脊形波导的模式特性及其等离子体色散效应

本文运用有效折射率法和WKB法对具有梯形状截面的硅脊形波导的模式特性作了分析,导出了TE模和TM模的模方程以及截止方程,并运用一阶微扰法对因波导顶部注入载流子而引起的模式调制的大小作了数值估计。其结果可为全硅光波导器件的研制提供指导。     

测量钢化玻璃表层应力的漏波导方法

本文报道利用漏波导方法测量钢化玻璃的表层应力。通过基模的双折射引入有效表层应力,并制作出相应的测量装置。对风冷钢化、化学钢化和慢退火玻璃,测量了有效表层应力,并在理论上分析了测量精度。     

基于硅波导的喇曼光放大器

在硅波导上添加反向偏压的PIN结构,当波导产生受激喇曼散射时,可以将波导中双光子吸收(TPA)产生的光生自由载流子扫出波导,降低了波导的非线性损失,极大地提高了硅波导中泵浦光对信号光的喇曼增益。为了应用已经非常成熟的硅工艺,并且应用硅波导使器件小型化,根据法布里-帕罗(F-P)腔和行波放大器理论,在硅波导两端的解理面蒸镀增透膜,应用这种波导的喇曼效应设计了一种光放大器,即基于硅波导的喇曼光放大器。建立了计算放大器增益的方程,给出了不同波导长度和输入功率情况下的放大器增益,得出适当增加波导长度和泵浦光功率可以得到较高喇曼增益的结论。基于硅的光放大器有较高的饱和功率且没有泵浦源的限制,通过调整泵浦激光的波长可以放大不同波长的信号光。     

PPQ共轭有机聚合物平面光波导的非线性传输特性的实验研究

从实验上研究了聚苯基喹恶啉（ＰＰＱ）共轭有机物平面光波导中的飞秒光脉冲的非线性传输特性，难过研究其光波导中由于自相位调制效应而导致的光谱展宽，得到了ＰＰＱ的非线性折射率，同时表明ＰＰＱ共轭有机物平面光波导中具较大的非线性效应，有可能制作较理想的全光器件。     

Stress reduction in planar waveguide using polymer top layer

Planar optical waveguides consisting of layers from different materials created at elevated temperatures usually exhibit substantial stresses. By controlling the layer thickness of polymeric top layer on planar waveguide structures, it is possible to use very thin layers for stress compensation, significantly reducing required deposition times. It is possible to reduce birefringence within planar device by controlling top polymer layer thickness with thermal expansion coefficient greater than silica or PMMA.     

Control of birefringence using polymer as cladding layer in optical planar waveguides

We demonstrate theoretically that a polymer layer, when used as cladding layer for silica-based planar optical waveguides on a silicon substrate, can substantially reduce birefringence. Multilayer planar optical waveguides usually exhibit stresses that are caused by thermal-induced strains that originate from the bonding of the layers, in addition to intrinsic strains. Effect of various intrinsic properties on thermal stress as a function of thickness of the guiding layer is studied. It is shown that it is possible to achieve the thermal stress free and, hence, the stress-induced birefringence free waveguide devices by proper waveguide designs.     

Evaluation of polycarbonate substrate hologram recording medium regarding implication of birefringence and thermal expansion

In this paper, we evaluate photopolymer media using a polycarbonate (PC) substrate. In holographic data storage medium, substrates that sandwich the photopolymer material are needed to protect the photopolymer material against exogenous shock and open air. An optical glass such as BK-7 is normally used as a substrate, but a PC substrate has a cost advantage and is easy to fabricate compared with optical glass. For holographic recording and reading, however, the high birefringence and high thermal expansion of a PC substrate are significant problems. First, we analyze the degree of degradation of output power by the polarization change and estimate the threshold value of birefringence to record hologram normally. Next, we estimate the temperature tolerance of hologram readout with polycarbonate substrate hologram medium. These analyses results indicate the possible usage of the PC substrate as holographic recording media.     

Design and numerical analysis for low birefringence silica on silicon waveguides

A new fabrication technology for three-dimensionally buried silica on silicon optical waveguide based on deep etching and thermal oxidation is presented.Using this method,a silicon layer is left at the side of waveguide.The stress distribution and effective refractive index are calculated by using finite element method and finite different beam propagation method,respectively.The results indicate that the stress of silica on silicon optical waveguide fabricated by this method can be matched in parallel and vertical directions and stress birefringence can be effectively reduced due to the side-silicon layer.     

光学玻璃应力双折射叠加

为解决在光学玻璃应力双折射测量中遇到的双折射叠加问题,利用光学等效原理,使用一个线性双折射模型和一个旋转器来代替叠加模型。对叠加的情况做了分析和计算,得到了叠加后的特征延迟、主应力方向和旋转角随两个应力模型主应力方向夹角变化的曲线。理论分析表明,应力双折射叠加不是应力双折射的简单相加,而是与叠加模型各自的应力双折射值和主应力方向的夹角有关。实验结果与理论计算相吻合。应力双折射叠加对实际光学玻璃测试造成不良影响,使测量精度降低,特别是有透光支撑机构或折射液容器的情况下,应力双折射叠加的影响不可忽略。     

Stress-induced birefringence control in optical planar waveguides

For what is to our knowledge the first time, the thermal-stress formula in analytical form is derived for the core layer in an optical planar waveguide by the thin-film approximation, which is based on a closed-form solution in multilayered isotropic structures off the edges. This formula indicates that elastic, thermal, and structural parameters can affect the magnitude of the stress. Using the formula, one can remove thermal stress and hence stress-induced birefringence by proper waveguide design.     

Surface stress measurement by the optical waveguide effect in thermally-tempered float glass

Float glasses have tin-diffused layers on one side. These layers show an optical waveguide effect caused by refractive index gradients in the layer. Surface stress, caused by tempering, gives different refractive index distribution for TM and TE waves via the stress birefringence effect. Non-destructive and rapid stress determination is possible by observing the effective index distributions of propagating modes in TM and TE waves.     

Thermal stresses in optical waveguides

Birefringence of optical waveguides is closely related to the anisotropy of thermal stresses in the core. Closed-form solutions for estimating the thermal stresses in the cladding layers and in the core of an embedded channel waveguide are presented. The solutions are verified by finite-element simulation. It is found that the thermal stress in the core in the direction perpendicular to the wafer cannot be ignored, and one can tune the core stress anisotropy in the plane normal to the light-propagation direction by varying the thermal-expansion mismatch between the upper cladding and the substrate.     

Optical properties of polymer poly(phthalazinone ether sulfone ketone) film waveguide

The optical properties of novel polymer poly(phthalazinone ether sulfone ketone, PPESK) film waveguide are studied by prism coupler. The optical properties of PPESK-8020, including refractive index, birefringence, thermo-optical coefficient and optical loss, are demonstrated. This kind of material has the advantages of low optical loss (less than 0.24 dB/cm at 1310 nm and 0.52 dB/cm at 1550 nm) and high thermal stability (1% weight loss temperature: 488 ℃). Due to these excellent properties, it may have great potential in optical waveguide applications.