共查询到20条相似文献,搜索用时 593 毫秒
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Yingtao Hu Marianna Pantouvaki Joris Van Campenhout Steven Brems Inge Asselberghs Cedric Huyghebaert Philippe Absil Dries Van Thourhout 《Laser \u0026amp; Photonics Reviews》2016,10(2):307-316
High performance integrated optical modulators are highly desired for future optical interconnects. The ultra‐high bandwidth and broadband operation potentially offered by graphene based electro‐absorption modulators has attracted a lot of attention in the photonics community recently. In this work, we theoretically evaluate the true potential of such modulators and illustrate this with experimental results for a silicon integrated graphene optical electro‐absorption modulator capable of broadband 10 Gb/s modulation speed. The measured results agree very well with theoretical predictions. A low insertion loss of 3.8 dB at 1580 nm and a low drive voltage of 2.5 V combined with broadband and athermal operation were obtained for a 50 μm‐length hybrid graphene‐Si device. The peak modulation efficiency of the device is 1.5 dB/V. This robust device is challenging best‐in‐class Si (Ge) modulators for future chip‐level optical interconnects. 相似文献
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基于插入损耗的光纤信号调制器 总被引:1,自引:0,他引:1
基于光纤连接的横向偏移造成的插入损耗研制了一种的新型的光纤信号光调制器。调节对接光纤的横向偏移,可以调节对接光纤间的光耦合效率,利用调制信号调制横向偏移可实现对光纤传输光信号的调制。实验中,将调制电信号放大并加载于压电陶瓷使其振荡,由此控制对接光纤的横向偏移与调制信号同步变化,实现了对下一级光纤输出端光强的调制。这种光纤信号调制器主要针对光的振幅调制,实验中获得调制度优于95%,信噪比约为20dB,带宽约为200kHz。具有价格低廉、调制度高的特点,可应用于光纤传输信号的调制及信号斩波等。 相似文献
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Kuniharu Takizawa 《Optics Communications》1981,37(5):345-348
One-dimensional focusing and optical modulation have been achieved using a Fresnel light modulator (FLM) based on a Fresnel lens consisting of Ti-diffused channel waveguides on LiNbO3. By this device, the height of diffraction pattern near the focal point is modulated with an applied voltage while the focusing effect is almost kept. The experimental results obtained from the FLM with 13 zones at 633 nm are as follows: the focal length is 12.4 cm, the full width of beam at half power 47 μm, the half-wave voltage 28 V, the extinction ratio 10.9 dB and the insertion loss 11.6 dB. 相似文献
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Hai-Young Lee 《Optical and Quantum Electronics》1995,27(5):487-494
A coplanar slow-wave electrode with periodic cross-tie overlays has been used to satisfy the essential phase velocity matching between the modulation and optical waves for wideband travelling-wave optical modulators. For an optimized modulator of 4 mm length at 1.3 m light wavelength, the calculated halfwave modulation voltage (23 V) is slightly higher than that (20 V) of conventional coplanar modulators but the 3 dB bandwidth (100 GHz) is much wider than the bandwidth limit (30 GHz) of walkoff-limited conventional coplanar modulators. The measured effective index (4.61) of the modulation wave is much higher than that (2.65) of conventional coplanar electrodes and agrees very well with the calculated one (4.25). 相似文献
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Katsutoshi Kubota Makoto Minakata Shoichi Saito Shingo Uehara 《Optical and Quantum Electronics》1978,10(3):205-210
A low drive-voltage optical modulator using a Ti-diffused UNbO3 optical waveguide has been fabricated. Stabilization against ambient temperature change was realized by using a miniature halfwave plate. The halfwave voltage, 3 dB bandwidth, optical insertion loss and extinction ratio were 3·8 V (at 1·06m wavelength), 850 MHz, 10 dB and 13 dB, respectively. A reduction scheme for the optical absorption caused by metallic electrodes, and an analysis of the modulator high frequency response are also reported. 相似文献
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提出一种新型基于Si2N2O基体的LiNbO3行波调制器,利用有限元方法对该调制器进行数值分析并获得调制器的优化结构尺寸.该新型调制器带宽达到120 GHz,半波电压为3.5 V,特性阻抗为50.2 Ω.结果表明该调制器具有大的调制带宽和良好的阻抗匹配,在未来光通信中具有很好的应用前景. 相似文献
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Different Electro-Optical Modulators for High Transmission-Data Rates and Signal-Quality Enhancement
We show how to optimize design parameters for different electro-optical modulators where the effective refractive index plays an essential role in the evaluation of the bandwidth structure. We investigate the effect of operating parameters on the switching, modulating voltage, device performance index, and optical bandwidth for different material-based electro-optical modulators and evaluate the transmission bit rate using nonreturn-to-zero (NRZ) coding transmission technique. As well as lithium niobate (LiNbO3), gallium arsenide (GaAs), and polymethylmethacrylate (PMMA), polymer EOMs have been developed for extensive use in high-speed- and high-transmission-performance optical-fibertransmission systems. This is because they offer the advantages of modulation exceeding multi-Gbit/s combined with a low driving voltage. 相似文献
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An optical fiber multi-function device consisting of a single gradient-index-rod lens and a multi-facet blazed reflection
grating is proposed to simultaneously realize functions of wavelength demultiplexing and optical signal distribution in a
multimode optical fiber transmission system. We analyzed the demultiplexing characteristics and the tolerance of optical components
using the ray trace method. This device can realize not only low loss optical signal distribution but also offers improved
demultiplexing characteristics in comparison with the previously proposed demultiplexer-multiposition switch. The following
characteristics are expected from the design using commercially available optical components: a working band of 0.64–0.88
μm, channel separation of 34–36 nm, 3 dB bandwidth of 27–28 nm, channel cross-talk of less than - 40 dB and minimum excess
insertion loss of 0.9–2.1 dB. 相似文献
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Deepak Kumar AgrawalShanti Bhattacharya 《Optics and Lasers in Engineering》2011,49(7):848-854
This paper presents the design, fabrication and characterization of a Variable Optical Attenuator (VOA). The VOA is based on a device known as the Mechanical Anti-reflection Switch (MARS) that has been well studied for modulation applications. Therefore, the requirements of the MEMS device need to be freshly ascertained and are done so in this paper taking the optical and MEMS parameters into account. In addition, the effect of the MEMS parameters on the optical ones and vise versa were also exploited in the design process. A good VOA should have a linear variation of attenuation with voltage and a large change in attenuation with a small change in voltage. In addition, the device should have as small an insertion loss as possible. Keeping this in mind, the dimensions of the device were chosen to achieve maximum performance. Four design variables were used to design MARS for the VOA application. This paper will discuss how they are related. A surface micro-machining fabrication method was developed using thermal evaporation and Plasma Enhanced Chemical Vapor Deposition (PECVD) techniques. It includes a fluoroform (CHF3) based reactive ion etching for silicon nitride. The devices were released using low surface tension liquids and Rapid Thermal Annealing (RTA). The achieved process yield was over 90%. Several devices were tested and attenuation up to 5.6 dB was observed experimentally. 相似文献
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We demonstrate, for the first time to our knowledge, optical bistability on a highly integrated silicon device, using a 5-microm-radius ring resonator. The strong light-confinement nature of the resonator induces nonlinear optical response with low pump power. We show that the optical bistability allows all-optical functionalities, such as switching and memory with microsecond time response and a modulation depth of 10 dB, driven by pump power as low as 45 microW. Silicon optical bistability relies on a fast thermal nonlinear optical effect presenting a 500-kHz modulation bandwidth. 相似文献
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A bandwidth-tunable optical passband filter with tunable attenuation is proposed. The filter, composed of a transmission liquid crystal array and high-resolution diffraction grating, was successfully demonstrated based on the compact spatial light design. Experimental results showed that the bandwidth, wavelength, and attenuation could be tuned by controlling the voltage applied on the liquid crystal array. The insertion loss was less than 3 dB;the attenuation tuning range was from 0 to 15 dB. The bandwidth tuning range was from 50 to 5000 GHz, which covered the full C band. The filter can meet the technical requirements of colorless-directionless-contentionlessflexible reconfigurable optical add/drop multiplexer. 相似文献
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1 IntroductionFOr LiNbO3 modulators, the bandwidth is mainly restricted by the microwaveattenuation of the travelling--wave electrode and the phase velocity ndsmatch betWeenmicrowave and optical wave in the devices. When the phase velocity matching issatisfied it is very i~rtant to decrease the microwave attenuation for expandingbandwidth. The thecrowave propagating lOSS is the main source Of the microwaveattenuation in the interactive region. The larger the cross-sectional area or the lOn… 相似文献
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M. Bello-Jiménez C. Cuadrado-Laborde A. Diez J. L. Cruz M. V. Andrés 《Applied physics. B, Lasers and optics》2011,105(2):269-276
We report an experimental study of an actively mode-locked fiber ring laser based on the development of an efficient in-fiber
amplitude modulator. Intermodal coupling induced by standing flexural acoustic waves permits the implementation of broad bandwidth
(1.5 nm), high modulation depth (72%), low-insertion-loss (0.75 dB), in-fiber amplitude modulators, operating in the MHz frequency
range. The experimental characterization of the laser as a function of the radio frequency voltage that controls the modulator,
the length of the active fiber, and the optical bandwidth of an intracavity filter implemented with a fiber Bragg grating
has led to an improved performance of the Erbium-doped fiber laser: optical pulses of 34-ps temporal width, 1.4-W peak power,
and 4.75-MHz repetition rate. 相似文献
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The characteristics of Z- cut LiNbO3 optical modulators with novel complex electrode are discussed by using the finite element method (FEM) and studied experimentally in this paper. The travelling wave electrode consists of upper and lower parts. It can easily realize phase velocity matching between microwave and optical wave and drastically reduce microwave electrode loss. An electrooptic modulator with larger than 100 GHz bandwidth and half wave voltage 6 V is designed, fabricated and measured. Vπ is 5.1 V and the attenuation coefficient a0 is 0.3 dB/(cm· GHz1/2 ). The experimental results show that the modulator has great potentiality for expanding bandwidth. 相似文献
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Ram Prakash Dwivedi 《Optics Communications》2011,284(5):1418-1423
We report, for the first time, on the design of a plasmonic modulator working on the principle of the elasto-optic effects in a directional coupling structure, utilizing three parallel metal-dielectric-metal waveguides. We propose to achieve the active switching of the power propagation using the elasto-optic effect and optimize the extinction ratio of the optical modulation. The device is characterized and numerically analyzed using the finite-element-method at the wavelengths of 1.55 μm. For the modulator length of 2.33 μm, the extinction ratio of the modulation is nearly 14 dB, and the calculated attenuation loss is 4.5 dB. The calculated driving voltage is 4.8 V for the given modulator. The effect of the applied voltage on the modulation is also analyzed. 相似文献
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Yao Zhang 《Optics Communications》2010,283(10):2140-276
A polarization beam splitter with wide bandwidth and simple structure in air-hole-based periodic dielectric waveguides has been proposed and designed. Operation principle of the device is based on different directional coupling properties of beams in TE and TM polarizations in parallel periodic dielectric waveguides. Performances have been evaluated by a finite-difference time-domain simulation. Results show that the polarization beam splitter provides a wide bandwidth of 113 nm with both a high extinction ratio (higher than 21 dB) and a low insertion loss (less than 1.5 dB) for optical communication wavelengths at ∼1.55 μm. Moreover, the performances of the polarization beam splitter are insensitive to longitudinal alignment errors in the coupling region, which is desirable for device fabrication and practical application. 相似文献