共查询到20条相似文献,搜索用时 31 毫秒
1.
Sugimoto Y. Ikeda N. Carlsson N. Asakawa K. Kawai N. Inoue K. 《Quantum Electronics, IEEE Journal of》2002,38(7):760-769
An AlGaAs-based near-infrared 2-D photonic crystal (PC) with an air-bridge structure featuring defect waveguides has been developed. For the sample without defect waveguides, measurements of the optical transmission characteristics in the wavelength range from 850 nm to 1100 nm showed a deep attenuation due to a bandgap with 30-35 dB attenuation and transmittance of nearly 100% for the guided modes. Optical propagation properties of defect waveguides were obtained by two methods: measurements of transmission spectra and plan-view observations of the optical beam trace along the waveguide with an infrared-vidicon camera. 3-D finite-difference time-domain simulations for the band structure and transmission spectra in the air-bridge slab with and without defect waveguides have revealed the appearance of four defect propagation modes specific to the defect waveguide, between two slab modes for the defect-free photonic crystal slab. These defect modes were experimentally identified in the measured transmission spectra 相似文献
2.
This paper describes the investigation of the waveguide properties of a silicon-on-insulator (SOI)-based two-dimensional photonic-crystal slab. It is found that coupling between transverse-electric (TE)-like defect modes and transverse-magnetic (TM)-like slab modes occurs in some frequency range due to structural asymmetries in the vertical direction. This TE-TM coupling, together with the smaller refractive-index contrast between the slab and dielectric cladding, results in propagation losses for a line-defect waveguide in an SOI structure. The paper also presents optimization methods for obtaining a wide lossless propagation band using such a line defect. 相似文献
3.
4.
为了研究多掺杂一维各向异性光子晶体的光学特性,采用传输矩阵法计算了光波通过多掺杂一维各向异性光子晶体的透射率。经数值模拟得到:光通过该结构光子晶体后,TE波和TM波的透射谱中随掺杂层个数的变化出现了单、双及多缺陷模,禁带中缺陷模的个数随掺杂层数的增大而增多,缺陷模的位置随掺杂层光学厚度的变化向短波方向移动,TE波和TM波的缺陷模能完全分开,透射谱的这一特点为设计制作单、双通道滤波器提供了理论依据。 相似文献
5.
Galli M. Bajoni D. Belotti M. Paleari F. Patrini M. Guizzetti G. Gerace D. Agio M. Andreani L.C. Peyrade D. Chen Y. 《Selected Areas in Communications, IEEE Journal on》2005,23(7):1402-1410
The dispersion of photonic modes in one-dimensional (1-D) and two-dimensional (2-D) patterned silicon-on-insulator (SOI) waveguides, also containing line defects, is fully investigated both above and below the light line. Quasi-guided (radiative), as well as truly guided modes are probed by means of angle- and polarization-resolved microreflectance and attenuated total reflectance measurements. For the 1-D case, the sharp resonances observed in reflectance spectra are analyzed in terms of the Airy-Fano model, and the measured linewidths are shown to be very close to theoretical predictions. In the 2-D lattices containing W1 line defects the presence of a supercell repetition leads to the simultaneous excitation of defect and bulk modes which are folded in a reduced Brillouin zone. The measured dispersion is in very good agreement with full three-dimensional calculations based on expansion on the waveguide modes, indicating that a deep understanding of the propagation properties of patterned SOI waveguides is achieved. 相似文献
6.
Sugimoto Y. Tanaka Y. Ikeda N. Nakamura H. Kanamoto K. Ohkouchi S. Watanabe Y. Inoue K. Asakawa K. 《Selected Areas in Communications, IEEE Journal on》2005,23(7):1308-1314
We have experimentally demonstrated two- dimensional (2-D) photonic crystal (PC) waveguides (WGs) such as straight, bent, Y-branch, directional coupler (DC), and quantum dots (QDs)-based nonlinear optical (NLO) WGs using a GaAs air-bridge membrane with triangular-lattice line-defect WGs. These WGs are necessary for a 2-D PC-based symmetric Mach-Zehnder (PC-SMZ) type ultrafast all-optical switch. Experimental results on the clear observation of the optical interference at the Y-junction DC, nonlinearity-induced phase shift at the NLO waveguide, and transmission spectra in the total PC-SMZ WG configuration will be addressed, as well as measured results on each WG element. 相似文献
7.
8.
一种缓变结构一维光子晶体的缺陷模研究 总被引:3,自引:2,他引:1
利用传输矩阵方法,研究了单折射率层缓变准周期结构一维光子晶体存在不同缺陷时的缺陷模。结果表明,当该准周期结构中存在缺陷时,引入了缺陷模,且缺陷模与缺陷层的位置和结构参数相关。缺陷层不同,缺陷模的位置及共振透射峰也不同。随着缺陷层光学厚度的增大,缺陷模波长向长波方向移动。 相似文献
9.
10.
2-D metallic photonic crystals without defects, with point defects, and with a Fabry-Perot (F-P) defect are characterized by terahertz time-domain spectroscopy. The metal parallel-plate waveguide (PPWG) with single TEM-mode propagation is used as a tool to simulate 2-D photonic crystals in free space. The 2-D metallic photonic-crystal structures were fabricated by coating Au on an SU-8 polymer cylinder array. Wide terahertz bandgaps were observed in the photonic crystals within the PPWG. The experimental measurements have excellent agreement to 2-D photonic-crystal theory without defects. Defect modes are observed in the samples with defects and show the F-P defect has a strong localization effect 相似文献
11.
Baba T. Motegi A. Iwai T. Fukaya N. Watanabe Y. Sakai A. 《Quantum Electronics, IEEE Journal of》2002,38(7):743-752
Straight single-line defect optical waveguides in photonic crystal slabs are designed by the finite difference time-domain method and fabricated into a silicon-on-insulator (SOI) wafer. By employing an airbridge structure, clear light propagation for both polarizations is observed without any leakage along the waveguide. This experimental result is well explained by photonic bands of pure guided modes. Minimum propagation loss is estimated to be 11 dB/mm. This value is lower than that reported so far for three-line-defect waveguides with an SOI slab structure and almost comparable to that for an index confinement waveguide with a rectangular Si core. This propagation loss is dominated by the scattering loss by some irregularities. However, photonic crystal waveguides have the possibility of an essential lower scattering loss than in the index confinement waveguide because of the inhibition of radiation modes by the photonic bandgap 相似文献
12.
Shimada R. Yablonskii A.L. Tikhodeev S.G. Ishihara T. 《Quantum Electronics, IEEE Journal of》2002,38(7):872-879
The transmission properties of a 2-D photonic crystal slab with an exciton resonance are investigated experimentally and theoretically. Good agreement between experiment and scattering matrix based theory is obtained. The photonic crystal slab is composed of a square lattice of etched square holes in a quartz substrate, filled by an inorganic-organic semiconductor and covered by a polystyrene guiding film. We demonstrate that the transmissivity of the structure shows pronounced dips, which originate from the excitation of quasi-guided modes in the photonic crystal slab. The measured and calculated angular dependence of the energy of these dips and their optical activity allow us to identify the physical properties of the quasi-guided modes, such as their symmetry and distribution of electromagnetic field 相似文献
13.
实现多种通道滤波功能的一维光子晶体缺陷模 总被引:5,自引:1,他引:4
利用传输矩阵法研究一维光子晶体B(AB)m(ACB)n(AB)mB的缺陷模,结果发现:随n的增加,B(AB)8(ACB)n(AB)8B的透射谱出现与n值对应的共振缺陷模,具有超窄带多通道滤波的特性;当n=1,随着C层介质光学厚度奇数倍增加,透射谱中出现奇数条共振缺陷模,具有超窄带奇数通道滤波特性;当n=1,随着C层介质光学厚度偶数倍增加,透射谱中出现两条共振缺陷模,具有超窄带双通道滤波特性。当n=1,缺陷模频率处局域电场强度随m的增加而增强,而随C层光学厚度奇数倍增加,缺陷模频率处局域电场强度不变,但局域范围扩大。这些光学传输特性,为研究、设计新型光学器件提供指导。 相似文献
14.
为了分析结构参量对正负折射率材料1维光子晶体缺陷模的影响,利用传输矩阵法计算了基于正负折射率材料含正折射率缺陷1维光子晶体B(AB)m(ACB)n(AB)mB的透射谱,分析了各参量对该结构1维光子晶体缺陷模的影响,并用波动理论定性分析了多通道滤波器形成的原因。结果表明,在各介质层的光学厚度绝对值都为0/4的情况下,每个禁带中都有n个超窄的透射峰,相邻两个透射峰间距比相同结构下正折射率情况的宽;当n=1时,随着C层介质光学厚度以0/4的k倍增加,透射谱中同一禁带内出现了k条透射峰;当n2时,透射谱中同一禁带内出现了nk条透射峰。该研究结果对可调多通道滤波器的设计和研究有一定的参考价值。 相似文献
15.
研究了太赫兹波垂直通过具有周期性亚波长环形空气槽阵列的金属-介质-金属三层结构的透射谱特性,以及与表面等离子体谐振的关系。共振模式电场分布与色散曲线分别表明:表面等离子体具有束缚性,表面电磁波的传输机制与能量流动过程,透射谱的两个共振峰与传播性的表面等离子体模式、局域化的表面等离子体模式及其耦合有关。改变结构的几何参数,其共振峰变化趋势进一步印证了以上观点,并且空气环中激发的准波导效应也影响了太赫兹波的传输。 相似文献
16.
一维缺陷光子晶体多个禁带中的窄带缺陷模 总被引:2,自引:1,他引:1
用特征矩阵法研究了一维缺陷光子晶体的透射谱。结果发现:在一维缺陷光子晶体的透射谱中的多个禁带内都有窄带缺陷模,窄带缺陷模的波长越大,其宽度越大;当入射角增大后,波长越长的窄带缺陷模的强度变化越小,位置向短波方向移动越多,且S偏振光与P偏振光的窄带缺陷模的分离越大;增大一维缺陷光子晶体中周期性介质的厚度,窄带缺陷模的波长和移动的范围都增大。本研究对一维缺陷光子晶体的窄带缺陷模的选择使用具有重要意义。 相似文献
17.
18.
构造和研究了光子晶体插入式二元缺陷和替代式二元缺陷微腔的光学传输特性,结果表明:随着二元缺陷自身周期数增大,微腔透射谱中分立缺陷模的数目增加,且替代式二元缺陷微腔分立缺陷模多于插入式二元缺陷微腔;随着缺陷高折射率介质厚度的增大,二元缺陷微腔的缺陷模向中间靠拢呈现简并趋势,同时禁带两侧出现多组双缺陷模,且高频一侧出现双缺陷模多于低频一侧,但替代式二元缺陷微腔出现的双缺陷模数目多于插入式二元缺陷微腔;随着缺陷低折射率介质厚度增大,插入式二元缺陷微腔的缺陷模向低频方向移动同时呈现耦合分开趋势,且透射率逐渐降低,而替代式二元缺陷微腔的缺陷模则向中间靠拢呈现简并趋势,同时缺陷模整体向高频方向缓慢移动,而透射率保持100%不变。光子晶体二元缺陷微腔的光传输特性为光学滤波器、光学开关和激光器等的设计提供了参考。 相似文献
19.
20.
Dependence of transmission spectra on director orientation in the photonic crystal with a liquid crystal layer
下载免费PDF全文
![点击此处可从《光电子快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The transmission spectra of one-dimensional(1D) photonic crystals(PCs) with parallel and twisted nematic liquid crystals(LCs) as defect layers are discussed by 4 × 4 matrix method,respectively.The results show that the photonic band gap(PBG) mainly depends on the periodic arrays of dielectric composites.The orientation of director and the symmetry of the director configuration have important influence on the location and amplitude of defect modes.The location and amplitude of defect modes can be controlled conveniently by changing the orientation of director.The symmetry of the director configuration can help us understand the defect modes spectra. 相似文献