共查询到20条相似文献,搜索用时 31 毫秒
1.
S. Wolff A.R. Giehl M. Renno H. Fouckhardt 《Applied physics. B, Lasers and optics》2001,73(5-6):623-627
A technology for the fabrication of metallic waveguide mirrors is developed. Plane and curved waveguide mirrors, the latter
acting in the same way as cylindrical lenses, are realized in benzocyclobutene (BCB) film waveguides. The waveguide mirror
structure is dry-etched into the BCB film waveguide. To enhance the reflectivity of the waveguide mirrors, the waveguide edge
is metallized. The BCB film waveguide mirrors are characterized with respect to waveguide attenuation and mirror reflectivity.
The waveguide attenuation of the processed BCB waveguide is 0.5 dB/cm. Ag-coated BCB waveguide mirrors show a reflectivity
of 71%. The efficiency of total internal reflection (TIR, i.e. in the case without metallization) at the dry-etched waveguide
edge is 74%. As an application of the BCB waveguide mirrors a hybrid integrated optical module for Fourier-optical transverse
mode selection in broad area lasers (BAL) is proposed.
Received: 16 May 2001 / Published online: 23 October 2001 相似文献
2.
Analysis of temperature profiles of thermo-optic waveguides 总被引:1,自引:0,他引:1
The temperature profiles of thermo-optic waveguides are analyzed by the finite element method. The heat generated by a thin-film heater causes the temperature of a nearby waveguide to increase. The analysis results show that thermal coupling is a function of the waveguide spacing and depth. Thermal coupling increases with the waveguide depth but decreases with the waveguide spacing. Thermal coupling could be reduced by placing a cooler on the adjacent waveguide or etching a deep trench between the waveguides. The cooler can reduce the coupling, but it is not effective for deep waveguides. For the trenched structure, the temperature of the heated waveguide increases as the trench depth increases; however, the temperature of the nearby waveguide will decrease. 相似文献
3.
一种温度不敏感型阵列波导光栅的研究 总被引:3,自引:3,他引:0
研究了的一种新型温度不敏感型阵列波导光栅(AWG)。该新型温度不敏感型阵列波导光栅的波导采用混合材料的波导结构,该混合材料波导通过在石英波导芯层上旋涂聚合物材料的上包层,达到改变波导温度特性的目的,使得阵列波导光栅的温度敏感性降低。通过理论分析和有限差分方法研究了其中两种结构:三层混合材料波导构成的阵列波导光栅和四层混合材料波导构成的阵列波导光栅,计算了该新型温度不敏感型阵列波导光栅的温度特性。结果表明,在一定的设计下,温度变化0~50℃时,这两种温度不敏感型阵列波导光栅的最大波长漂移量小于0.03nm,不到无温度控制时常规阵列波导光栅最大波长漂移量的4%。 相似文献
4.
I. E. Golentus A. Yu. Gaevskii 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2014,8(3):462-469
The propagation of an X-ray beam through a plane-parallel waveguide is studied with allowance for Bragg grazing diffraction on the crystalline structure of the plates. Expressions for the waveguide modes are obtained and nondecaying waveguide modes are shown to exist at angles that are larger than the critical one (the angle of total external reflection), which permits one to increase the capture angle of radiation incident on the waveguide. The calculated intensity at the waveguide output is compared with the intensity of waveguide modes in the absence of grazing diffraction in the waveguide material. 相似文献
5.
An air channel inside a silver metal film is usually used as a typical Channel Plasmon Polariton (CPP) waveguide. This paper presents research on the basic properties of this waveguide using the Finite Difference Time Domain(FDTD) method. The relationship between transmission power and structure of the waveguide is investigated. The simulation results show that the subwavelength trapezoidal CPP waveguide is superior to the rectangle CPP waveguide for controlling SPP radiation loss and enhancing the transmitted power. As a result, if the rectangle CPP waveguide is replaced by a trapezoidal CPP waveguide in certain integrated optical devices, their performance may be improved. 相似文献
6.
Fan-Yi Meng Kuang Zhang Fang Zhang Qun Wu Jong-Chul Lee 《Applied Physics A: Materials Science & Processing》2011,102(3):509-515
The design and characterization is described of a reconfigurable subwavelength waveguide based on magnetic metamaterial. The
waveguide is capable of reconfiguring its propagating mode from right-handed to left-handed, which can be applied in the design
of novel microwave and RF devices such as leaky wave antennas with broadened scanning range. The waveguide consists of a rectangular
metallic waveguide loaded by two pieces of different magnetic metamaterials, which are structured by the same cells—modified
split ring resonators (MSRRs)—with different arrangements. Positions of the two pieces of metamaterials in the waveguide can
be reconfigured separately by the control mechanism. The simulated transmission data show that the waveguide has a passband
below the cutoff frequency of the hollow waveguide either in the left-handed case or in the right-handed case. The extracted
constitutive parameters have demonstrated that the effective permittivity and permeability of the waveguide are simultaneously
negative in the left-handed case and positive in the right-handed case. The magnetic field and surface current distributions
in the waveguide confirm that the waveguide operates as can be expected. The influence of the control mechanism on the performance
of the waveguide is studied. It is shown that the influence is so minor that it can be neglected. 相似文献
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Sensitivity enhancement in TE mode nonlinear planar optical waveguide sensor with metamaterial layer
The dispersion equation of the TE mode nonlinear planar optical waveguide with metamaterial layer was derived, and the sensitivity of the waveguide sensor was analyzed. The influences of structural parameters on the sensitivity of the waveguide sensor were investigated. We verify that the waveguide sensor with metamaterial layer can dramatically enhance the sensitivity compared with other waveguide sensors. 相似文献
10.
Sanjeev Kumar Raghuwanshi 《Indian Journal of Physics》2010,84(7):831-846
In this paper we have studied the asymmetric versus symmetric planar waveguide in terms of their usefulness in optical fiber communication systems. We have explored the thin
waveguide versus thick waveguide first. Later on usefulness of asymmetric versus symmetric waveguide is carried out to target for WDM optical network application. All kinds of optical network components
are fabricated on Si substrate with the point of view of their application. Here asymmetric planar structure may be more useful
compared to symmetric waveguide in terms of their non-uniform power confinement properties. However, the symmetric waveguide
structure may be more useful for their high power confinement properties. It is well known that the thin symmetric waveguide
supports at least one mode. However the thick waveguide may support many even as well as odd modes. We study the power confinement
properties for symmetric as well as asymmetric waveguide structure. We conclude that higher order modes show the nonlinear
power variations. Mode field profile for various cases is discussed as well. Comparative study between asymmetric versus symmetric waveguide has a lot of significance in optical network area. It has been shown through analysis that in asymmetric
waveguide, the power flows more through film region in the case of fundamental mode. Power confinement properties for asymmetric
waveguide versus symmetric waveguide have been studied. 相似文献
11.
In a waveguide transducer that transmits an ultrasonic wave through a waveguide unit to a test structure, it is most preferred to send a non-dispersive ultrasonic wave of a narrow beam width. However, there is an unresolved conflict between the generation of the non- or less-dispersive wave and the transmission of a narrow-beam wave into a test structure. Among others, the thickness of the waveguide unit in a waveguide transducer is the key variable determining these two conflicting criteria, but the use of a uniformly-thick waveguide of any thickness cannot fulfill the two conflicting criteria simultaneously. In this study, we propose a specially-engineered tapered waveguide unit for the simultaneous satisfaction. An excitation unit is installed at the end of the thin region of the tapered waveguide and generates only the lowest non-dispersive shear-horizontal wave. Then the generated wave propagates through the tapered region of the waveguide unit and reaches the thick region of the waveguide with insignificant mode conversion to higher modes. If the tapered waveguide is used, the surviving lowest mode in the thick region of the waveguide is shown to carry most of the transmitted power and is finally propagated into a test structure. Because the beam size of the propagated wave and the thickness of the contacting waveguide region are inversely related, the thick contacting region of the tapered waveguide ensures narrow beam width. Numerical and experimental investigations were performed to check the effectiveness of the proposed waveguide-tapering approach. 相似文献
12.
利用机械调节波导宽边尺寸可变化波导波长,从而实现变频波束扫描相同的效果,针对窄边辐射波导行波阵的波束扫描特性进行了分析,以实现宽角波束扫描为目标,着重分析了不同辐射缝隙间距下变化宽边所能得到的最大波束扫描范围。设计了通过变化宽边尺寸实现宽角扫描的X波段窄边辐射波导缝隙阵,设计波束扫描范围指向波导馈入端,避开阵列法向辐射(此方向辐射效率较低),实现了29°的连续波束扫描范围,在波束扫描范畴内增益下降小于3 dB,辐射效率大于62%;设计缝隙宽度3 mm, 波导长度约1 m(缝隙数40),单根波导缝隙天线可实现高功率微波功率容量70 MW。 相似文献
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We study adiabatic transformation in optical waveguides with discrete translational symmetry. We calculate the reflection and transmission coefficient for a structure consisting of a slab waveguide that is adiabatically transformed into a photonic crystal waveguide and then back into a slab waveguide. The calculation yields high transmission over a wide frequency range of the photonic crystal waveguide band and indicates efficient coupling between the slab waveguide and the photonic crystal waveguide. Other applications of adiabatic mode transformation in photonic crystal waveguides and the coupled-resonator optical waveguides are also discussed. 相似文献
15.
一种高品质中空金属光波导 总被引:3,自引:0,他引:3
讨论了高品质中空金属光波导的工作原理及其制作工艺,制备了以金和银作为波导材料的中空波导管,并对空芯以及充入不同透明液体的液芯波导的透光特性进行了测试,结果表明:与中空介质波导相比,中空金属波导具有光传输损耗低,透过率对波导弯曲与失调不甚敏感等优点;而液芯金属波导的透光效率与透明材料的折射系数无关。文中描述了在特定波段内“中空光纤”的原理,并报道了He-Ne和CO2激光在中空金壁波导传输的实验结果。 相似文献
16.
A. A. Egorov 《Optics and Spectroscopy》2010,109(4):625-634
The eigen and noneigen (leaky) modes of a three-layer planar integrated optical waveguide are described. The dispersion relation
of a three-layer planar waveguide and other dependences are derived, and the cutoff conditions are analyzed. The diagram of
propagation constants of the guided and radiation modes of an irregular asymmetric three-layer waveguide and the dependence
of the electric field amplitudes of radiation modes of substrate on vertical coordinate in a tantalum integrated optical waveguide
are presented. The operating principles of an absorption integrated optical waveguide sensor are investigated. The dependences
of sensitivity of an integrated optical waveguide sensor on the sensory cell length, the coupling efficiency of the laser
radiation into the waveguide, the absorption cross-section of the studied material, and the level of additive statistical
noise are investigated. Some of the prospective areas of application of integrated-optical waveguide sensors are outlined. 相似文献
17.
研究了一种新型的过模圆转弯波导,可实现圆波导TM01模的转弯传输。介绍了这种过模圆转弯波导的基本原理:即沿转弯平面插入一块金属板,将圆波导转换为两个半圆波导。圆波导TM01模在半圆波导中转换为半圆波导TE11模,经转弯传输后,重新将半圆波导TE01模转换为圆波导TM01模,从而实现圆波导TM01模的转弯传输。基于这一原理设计了一个中心频率为2.856 GHz、转弯45°的过模圆转弯波导,并进行了数值模拟和实验研究。实验结果表明:其转弯半径为123.7 mm,转弯半径较小;在中心频点2.856 GHz处,传输损耗约为0.247 dB,驻波系数为1.217;在2.75~2.95 GHz的频率范围内传输损耗小于0.53 dB,驻波系数小于1.34。 相似文献
18.
硅基二氧化硅波导和SOI脊型波导应力双折射研究 总被引:4,自引:2,他引:2
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. 相似文献
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