【作者】 胡挺；

【导师】 杨建义；

【作者基本信息】 浙江大学 ， 微电子学与固体电子学， 2014， 博士

【摘要】 半导体微电子行业经历了近50年的飞跃发展,如今在单个集成电路芯片上集成的逻辑门超过千万个。然而,长期以来光电子器件主要被III-V族材料所统治,如何复制硅材料在微电子领域取得的巨大成功,使用这种间接带隙材料实现低成本、高密度集成的光子器件,是从事硅光子研究人员不懈努力的方向。绝缘衬底上硅(SOI, Silicon on Insulator)材料具有高折射率差,可在CMOS (Complementary-Metal-Oxide-Semiconductor)兼容工艺下实现结构紧凑的光子器件。且硅材料具有良好的热光效应和等离子色散效应,可用来实现对光子器件的调谐控制。由环形光波导和直光波导耦合而成的微环谐振器是一个结构紧凑的光学滤波器,它可以用来构建多种不同用途的集成光学器件,包括光调制器、光开关、光插分复用器、光路由器、光传感器等。本论文以硅基微环谐振器为基本单元,对利用其滤波特性构建的箱型滤波器、波长选择光路由器以及Fano谐振器进行了理论研究和实验验证。主要的内容包含以下几个方面：1.设计了半径为10μm的二阶、三阶硅基串联微环滤波器,采用CMOS兼容工艺完成器件的制作。测试结果表明,器件能实现箱型滤波特性。二阶串联硅基微环滤波器的下路谱线顶部平坦,带内的功率起伏仅有O.11dB左右,3dB带宽约为0.31nm,消光比超过35dB,插损约为0.4dB。三阶微环滤波器下路端谱线3dB带宽为0.38nm,插损小于0.9dB,消光比超过39.5dB。三阶微环滤波器在热电极控制下可以实现整个FSR范围内的连续调节,热调谐效率为48.4mW/nm.动态响应特性测试结果显示,滤波器通道切换时间小于12.63μs。2.对光互连网络中的核心器件光路由器进行了深入研究。通过构建八端口路由器为例,给出了一种利用无源微环上下话路滤波器构建N端口非阻塞波长选择光路由器的通用设计方法。设计并实现了基于硅材料的四端口波长选择路由器。在实验测试得到的光传输谱线中,可以观测到该四端口路由器的12条路由光链路,它可以支持包含4个广播模式在内的13个非阻塞工作状态,所有通道间最差串扰约为-10dB。在测试的光谱范围内,利用微环的梳妆滤波(comb filter)特性能实现4组工作波长的同时路由,将器件的信息吞吐量提高4倍。为优化器件的串扰和插损,设计并实现了基于双环耦合交叉波导的硅基四端口路由器。测试结果显示,器件通道间最差的串扰大幅度降低,约为-21.56dB。部分光链路的插损可减小0.61dB。但该结构破坏了微环谐振器的comb特性,不可实现多组工作波长同时路由。因此,最后提出了性能更优越的基于串联双环箱型滤波器的硅基四端口波长选择路由器结构。3.研究了光谐振器中Fano谱线产生的原理,在SOI材料上实现了一个可以产生并控制Fano谱线形状的谐振系统。在这个系统中,Fano谐振谱线来源于在微环谐振器中谐振的两束光的干涉。Fano谐振谱线的线形可以通过控制这两束相干光进入微环谐振器前的相位差来进行调节。当相位差为0.5π或1.5π时,Fano谐振谱线具有最大斜率和高消光比。实验测试结果表明,通过控制热电极满足两束光的相位差条件,可以在微环谐振器的整个自由光谱区(FSR, Free Spectral Range)内获得消光比超过20dB的陡峭Fano谱线。更多还原

【Abstract】 After near50-year rapid development of the semiconductor and microelectronic industry, over10-million logic gates can be interated in a single chip today. However, optoelectronic devices are almost demonstrated by III-V group materials. How to duplicate the great success of the application of silicon in microelectronics and use this indirect-band-gap material to implement the low-cost, high-integration photonic devices is the direction for researchers to make the unremitting efforts.Silicon on Insulator (SOI) has the high refactive index difference, and can be utilized to fabricate the compact photonic devices by CMOS-compatibe process. And the thermo-optic (TO) effect and plasma dispersion effect of silicon can be used to control the SOI-based photonic devices. Microring resonator (MRR), which is constructed by ring and straight waveguides, is a compact optical filter. It is a versatile element used for various applications, such as optical modulators, optical switches, optical add-drop multiplexers, optical routers and sensors.This thesis makes the therotical analysis and demonstration of box-like optical filters, wavelength-selective routers and Fano resonators that based on the filter characteristic of the fundamental element-silicon MRR. The main works are listed as follows:1. The box-like optical filters baed on second-and third-order series coupled10-um microring resonators (MRRs) are designed and demonstrated by the CMOS-compatibe process. The experimental results show that they both realize the box-like filter characteristic. The top of the optical transmission spectrum of the second-order filter’s drop port is very flat with an intraband ripple of0.11dB. The3dB bandwith, insertion loss and extinction ratio (ER) are0.31nm,0.4dB and larger than35dB, respectively. Those of the optical transmission spectrum of the third-order filter’s drop port are0.38nm, less than0.9dB and over39.5dB, respectively. The filter response is successfully tuned by one free spectral range (FSR) through TO effect with a tuning efficiency of48.4mW/nm. The dynamic tuning measurement shows that the filter channel switch time is less than12.63μs.2. The key element of the optical interconnects-optical routers are studied and demonstrated on SOI platform. An eight port optical router is presented as an example to illustrate the design method for establishing an N port non-blocking wavelength-selective router. Then we design and fabricate a four port router with SOI. The possible12I/O routing paths are experimentally observed. Thirteen nonblocking operating states, including four broadcasting states, with worst-case corsstalk of-10dB are supported. By using the comb filter characteristic of MRRs, each path has the ability to route four group wavelengths simultaneously in the measured spectral range, which can increase the data throughput by4times. In order to reduce the device’s crosstalk and insertion loss, a four port router based on two MRRs coupled to crossing waveguide is designed and fabricated. Mearsured results show that the worst crosstalk decreases a lot and is to be around-21.56dB. The insertion loss of some optical paths is reduced about0.61dB. But this structure destroys the MRR’s comb characteristic and can’t realize the simultaneous routing of multiple groups of wavelengths. Hence, another new four port routers based on series coupled MRR box-like filters with the superior performance is proposed.3. The generation principle of Fano resonance is studied and a resonant system that can produce and control Fano resonance is demonstrated on SOI platform. In this system, the Fano resonance originates from the interference of two beams resonant in the MRR. The shapes of the Fano resonances are tunable through controlling the phase difference of the two beams. Both largest slope and high ER are obtained when the phase difference is0.5π or1.5π. Experimental results show that Fano resonances with steep slope and ER over20dB are achieved in the whole FSR by controlling the microheaters to meet the phase condition.更多还原