基于波状PN结的低驱动电压电光调制器  

Low driving voltage electro-optic modulator based on wavy PN junction

作　　者：闫飞旭 陈鹤鸣 YAN Fei-xu;CHEN Homing(College of Electronic and Optical Engineering&College of Microelectronics,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;Bell Honors School,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学电子与光学工程学院、微电子学院,江苏南京210023 [2]南京邮电大学贝尔英才学院,江苏南京210023

出　　处：《光电子．激光》2020年第2期125-129,共5页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61571237,61077084)资助项目.

摘　　要：本文研究了一种基于波状PN结的低驱动电压电光调制器,该器件在光通信系统中可以获得较高的传输效率和较低的传输损耗。器件主要由光子晶体线缺陷波导和谐振腔组成。在光子晶体平板上下侧分别添加反向偏置电压,同时在波导中心区域引入谐振腔,通过在谐振腔区域添加不同浓度的掺杂,从而在线缺陷波导处形成波状PN结。根据等离子色散效应,在光子晶体两边施加反向偏置电压时会引起掺杂区硅基平板折射率的变化,从而导致光的透射率发生改变,以此达到调制的目的。采用时域有限差分法(FDTD)分析其时域稳态场强分布、模场分布和波状PN结参数对驱动电压的影响,结果表明:在驱动电压为1.04 V时,该器件可以实现中心波长为1 584.5 nm的TE模窄带宽通、断调制,且器件的消光比高达30.8 dB,插入损耗仅有0.5 dB,Q值高达1.4×10^4。An electro-optic modulator based on wavy PN junction resonator is proposed in this paper.The device can achieve higher transmission efficiency and lower transmission loss in optical communication system.The device consists of a line defect waveguide and a resonator in a two-dimensional photonic crystal plate.Reverse bias voltage is added to the upper and lower sides of the photonic crystal plate.At the same time,a resonant cavity is introduced in the center of the waveguide.By adding different concentrations of dopant in the resonant region,a wavy PN junction is formed in the line defect waveguide.According to the plasma dispersion effect,the refractive index of the doped silicon-based plate will change when the reverse bias voltage is applied on both sides of the photonic crystal,which will lead to the change of the transmittance of light,so as to achieve the purpose of modulation.Finite-difference time-domain(FDTD) method is used to analyze the steady-state field intensity distribution and mode field distribution in time domain and influence of parameters of wavy PN junction on driving voltage.The results show that based on the minimum driving voltage of 1.04 V,the narrow bandwidth on-off of TE mode with central wavelength of 1 584.5 nm can be realized.The extinction ratio of TE mode is 30.8 dB,insertion loss is only 0.5 dB,the Q value is as high as 1.4×10^4.

关 键 词：光通信 电光调制器 时域有限差分法 驱动电压 等离子色散 光子晶体 

分 类 号：TN15[电子电信—物理电子学]