共查询到19条相似文献,搜索用时 137 毫秒
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研究了在X切铌酸锂基底上制作沿Y方向传输光的电光长周期波导光栅的理论模型。利用有效折射率法和射线法进行理论分析获取波导的各项参数。针对所建议的波导光栅结构,将调谐电极置于波导两侧,无需跨过波导就可获得最大的电光调制。该结构的电极间距小(小于10μm),使得在较小的驱动电压(1.6V)下就可以实现阻带幅度高达28dB的长周期波导光栅。对该光栅模型的研究为开发低驱动电压的高速电光长周期光栅提供了理论依据。 相似文献
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电光调制器作为光通信系统中最重要的器件之一,其性能决定了光通信系统的传输性能,而电光调制器的电极结构、种类和设计都对调制器的性能有重要的影响。针对基于光纤布拉格光栅(FBG)的新型电光调制器电极展开了研究和设计,并通过数值计算方法,对模场重叠因子、电极结构参数以及模场重叠因子和FBG中心波长漂移量 的关系做了讨论,并由此对基于FBG的聚合物电光调制器的电极做了一系列的分析和研究。文中的研究对基于FBG的电光调制器的制作具有一定的指导意义,能够促进电光调制器的发展。 相似文献
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最近几年,宽带光通信系统的需要刺激了对高速集成电光器件的研究和发展,其中研制成功的最重要的器件之一是宽带电光调制器。宽带电光调制器是用高速电信号调制激光器来发射光波,利用光波实现高速大容量信息传输。宽带电光调制器按波导的外形结构可分为Y分支型和MZ干涉仪型,它们大多数是用 相似文献
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聚合物共面波导行波电极电光调制器 总被引:1,自引:1,他引:1
用聚合物材料BPAN-NT设计并初步成功制作了共面波导(CPW)行波电极电光调制器。用反应离子刻蚀(RIE)的方法制作脊波导,通过电晕极化使芯层有电光效应,利用电镀方法制作厚行波电极。对调制器的各项特性参数进行了测试,测得调制器的微波损耗系数0α=0.9 dB/cm.(GHz)1/2、在1.317μm波长上Vπ=250 V,由此算得芯层材料的电光系数3γ3=3.7 pm/V,同时测得消光比为13.49dB、插入损耗为18.6 dB,在8 GHz的微波频率上观察到了调制光信号,理论计算3 dB光调制带宽为43.77 GHz。 相似文献
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硅基槽型微环谐振器及其调谐特性研究 总被引:7,自引:7,他引:0
仿真和实验研究了含槽型(slot)光波导的反馈波导型微环谐振器的特性,将槽型光波导集成到Si基微环谐振器中,丰富Si基光波导的功能,为新型光电子器件的实现提供途径。通过锥形波导结构实现从传统波导到槽型波导的模式转换,减小传输损耗,采用时域有限差分法(FDTD)研究了光功率的分布和模式转换过程。结果显示,光功率逐渐转移到锥形结构两侧的槽型波导中并最终形成槽型波导中的传输模式,通过优化锥形结构能实现较高的模式转换效率,可以达到90%以上。采用电子束刻写技术和等离子刻蚀技术制备了反馈波导型槽型微环谐振器。实验显示,锥形波导能够实现模式的转换,光传输过程良好。通过在槽型波导中填充电光聚合物来改变槽型光波导的折射率,测量结果显示,传输谱谐振峰发生了明显移动,移动幅度达到5.6nm,器件具备很好的可调谐性。 相似文献
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为了研究能够在室温下实现稳定多波长输出的掺铒光纤激光器,采用了在激光谐振腔中引入正弦相位调制和偏振烧孔来抑制腔中模式竞争的方法。在线形谐振腔中,利用半导体光波导作为一个反射腔镜,并用正弦信号对其进行驱动。这样,半导体光波导可以等效成两个器件:一个对光信号产生移频反馈效果的正弦相位调制器,和一个诱使掺铒光纤中产生偏振烧孔的非线性相位延时器。通过实验,得到了10波长输出的稳定光谱。相邻波长间隔为0.32nm,功率谱比较平坦,起伏小于3dB。结果表明,相位调制和偏振烧孔的共同作用,可以有效的抑制由于掺铒光纤的均匀展宽效应引起的模式竞争。 相似文献
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Electro-optic (EO) modulator plays a very critical role in the optical communication systems. Here, we report a stimulated thin-film lithium niobate (LN) modulator with a half-wave voltage-length product of 1.8 V.cm, which can successfully achieve modulation and demodulation of a 1 GHz sinusoidal signal with an amplitude of 5 V in experiment. The optical loss caused by metal electrodes is reduced by optimizing the waveguide structure and depositing silica onto the waveguide, and group-velocity matching and characteristic impedance matching are achieved by optimizing the buffer silica layer and the electrode structure for larger bandwidth, which simultaneously improves the modulation efficiency and bandwidth performance. Our work demonstrated here paves a foundation for integrated photonics. 相似文献
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Design and performance of a polymer Mach-Zehnder interferometer electro-optic modulator at 1.55 μm 总被引:1,自引:0,他引:1
Based on poled guest-host electro-optic (EO) polymer DR1/SU-8, a Mach-Zehnder interferometer (MZI) EO modulator operated at 1.55 μm is proposed. For achieving high response speed and high EO modulation efficiency, both waveguide structure and electrode structure are especially optimized. The impedance match and less index mismatch are achieved. The final characteristic impedance of electrode is about 49.4 Ω, and the microwave index and the light-wave index are 1.5616 and 1.6006, respectively. The device is fabricated using wet-etching technique and inductively coupled plasma (ICP) etching technique, and its performance is measured at 1.55 μm. Experimental results show that when the applied voltage is tuned, the modulator can be changed from ON state to OFF state. The insertion loss at ON state is 12 dB and the extinction ratio between ON and OFF states is about 10 dB. The high response speed is in nano-second level for a square-wave signal. Therefore, the modulator possesses potential applications in high-speed optical networks on chip. 相似文献
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A modulator with micron dimensions, capable of optical modulation and switching in an integrated waveguide, is proposed. The proposed modulator uses surface plasmon resonance and an electro-optic polymer to modulate light which is guided in an integrated waveguide. Theoretical analysis of the modulator is presented for wavelengths of light in the visible and near infrared. Design criteria and dimensions of the modulator are discussed 相似文献
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This paper presents the joining of active nonlinear polymer waveguides with passive silicon nitride waveguides (SiO2-Si 3N4-SiO2) to form an integrated Mach-Zehnder modulator with a lateral electrode configuration on a silicon substrate. Passive and active waveguides are based on a silicon-nitride-strip guiding structure. In the active waveguide a nonlinear polymer layer is used to obtain an index modulation via the electrooptic effect. Despite the silicon nitride strip based guiding structure, 63% of the energy of the fundamental mode is guided in the nonlinear polymer (provided by Flamel Technology, Venissieux, France). Poling with field strengths up to 75 V/μm applied to the lateral electrodes has been employed to orient the chromophores. A half wave voltage of 35 V has been measured for an electrooptic coefficient of 5.8 pm/V at a wavelength of 1.3 μm. Optical loss measurements have been done on polymer and passive waveguides. The best results have been 1.8 dB/cm for the active and 0.78 dB/cm for the passive waveguides leading to a total loss of 6 dB for a modulator with an interaction length of 2.5 cm. The coupling loss between a laser diode and the passive waveguide structure was measured to be at least 4.6 dB using a microscope objective and piezo-electric displacement elements. Stability tests under atmospheric conditions have shown a decrease of the electrooptic coefficient which might be due to the hygroscopic behavior of the active polymer. The bandwidth of the modulator has been determined to be 4 MHz 相似文献
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Okada Y. Yan R.-H. Coldren L.A. Merz J.L. Tada K. 《Quantum Electronics, IEEE Journal of》1989,25(4):713-719
The variations in the absorption coefficient and the refractive index in the waveguide region of a double-heterostructure N-AlGaAs/p-GaAs/N-AlGaAs bipolar transistor carrier-injected optical modulator/switch are calculated theoretically using a band-tail model. The refractive index change is calculated by a Kramers-Kronig analysis of the absorption curve, which changes in the vicinity of the absorption edge primarily because of the effect of band-filling, band-gap shrinkage, and plasma dispersion associated with the presence of free carriers. The performance of bipolar transistor carrier-injected optical modulator/switch is analyzed on the basis of the calculated results, including the alpha-parameter and the maximum modulation depth. It is shown that small frequency chirping and high modulation depth with low absorption loss can be achieved by properly selecting the optimum operating conditions 相似文献
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为了便于分析Y波导调制器残余强度调制的产生机理,提出一种Y波导调制器残余强度调制的测试方法.系统采用Spartan-6系列的FPGA作为主控芯片,控制模数转换芯片ADS5560对经光电转换后的调制光信号进行采集,将采集到的数据打包后通过UART通信模式发送至PC机,获取Y波导调制器残余强度调制大小及波形信息.根据残余强度调制大小和波形信息分析模场改变引起的线性和杂散光与输出光的干涉两种机理产生的残余强度调制所占比例.测试结果表明,系统稳定性良好,对于Y波导调制器的开发有重要意义. 相似文献
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A novel integrated-optic focal-spot intensity modulator comprising an electrooptic (EO) phase-distribution modulator and a focusing grating coupler (FGC) in an EO polymer planar waveguide on a Si substrate is proposed and demonstrated. The integrated phase-distribution modulator is made up of three-finger top electrodes and a planar bottom electrode sandwiching the waveguide. The electrodes are used for both the poling process and the modulation of the phase distribution of the guided wave. The FGC couples the guided wave to a beam focused on a point in free space. The intensity distribution of the focused spot is modulated by altering the wavefront of the guided wave. The bottom metal electrode is extended to the place under the FGC and serves as a reflection film so that the output coupling occurs only into the direction of the air for increasing the efficiency. The device was designed and fabricated with an active polymer p-NAn-PVA (p-nitroaniline n-polyvinyl alcohol). An extinction ratio of the focal-spot intensity was higher than 3 dB at a modulation voltage of 30 V for 3-mm-long electrodes. The frequency response was measured to be flat over 2 MHz. The EO effect induced by poling showed no significant relaxation over 300 h in an unconditioned room (20-30°C) 相似文献