高信噪比反射式体布拉格光栅滤光片的设计方法  

Design Method of High Signal-to-Noise Ratio Reflective Volume Bragg Grating Filter

作　　者：郑丽丽[1,2,3] 晋云霞 孔钒宇[1,2,3] 莫建威 董元植[1,3] 孙静 Zheng Lili;Jin Yunxia;Kong Fanyu;Mo Jianwei;Dong Yuanzhi;Sun Jing(Laboratory of Thin Film Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Materials for High Power Laser,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center for Excellence in Ultra-Intense Laser Science,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]中国科学院上海光学精密机械研究所薄膜光学实验室,上海201800 [2]中国科学院大学材料与光电研究中心,北京100049 [3]中国科学院上海光学精密机械研究所强激光材料重点实验室,上海201800 [4]中国科学院超强激光科学卓越创新中心,上海201800

出　　处：《光学学报》2024年第21期11-19,共9页Acta Optica Sinica

基　　金：国家重点研发计划(2020YFA0714500);国家自然科学基金(61875212,U1831211);上海市战略性新兴产业发展专项基金(31011442501217020191D3101001);中国科学院国际合作项目(181231KYSB20200040);中国科学院战略性先导科技专项(A类)资助(XDA25020314)。

摘　　要：记录在光敏热折变玻璃中的反射式体布拉格光栅是密集波分复用和解复用的优良器件,但光栅两端耦合强度突变引起的旁瓣会导致信道间串扰,进而对复用和解复用效果产生影响。基于F矩阵理论,建立了反射式体布拉格光栅切趾理论模型,通过定义有效折射率调制度实现了对不同切趾体光栅衍射效率的归一化,并对余弦、高斯、双曲正割3种函数的切趾效果进行系统的对比与分析。基于此模型设计了一套C波段通用体布拉格光栅型滤光片,为高信噪比的反射式体布拉格光栅滤光片的研制提供了理论设计依据。Objective Wavelength division multiplexing(WDM)in optical fiber communications is widely recognized as the most effective method for increasing communication capacity due to its low cost and ease of implementation.Wavelength division multiplexing and demultiplexer devices(WDMDs)are essential components for implementing WDM technology and have remained at the forefront of optical multiplexing research.Volume Bragg gratings(VBGs)recorded in photothermo-refractive glass(PTRG)exhibit extremely narrow spectral bandwidths.These gratings are capable of filter different wavelengths of light by adjusting the incident angle,offering high efficiency,high transmission rates,low insertion loss,and excellent environmental stability.Therefore,they hold great potential for dense wavelength division multiplexing(DWDM)applications.However,the sidelobes caused by sudden changes in coupling strength at both ends of the grating will lead to interchannel interference,preventing the reduction of channel spacing and thereby affecting application performance.In periodic waveguide structures,a method to suppress sidelobes by varying the distribution of coupling strengths is known as apodization.Current research on apodization techniques for VBGs predominantly focuses on using a single function,such as sinc or Gaussian functions,to achieve sidelobe suppression.As far as we know,there has been no systematic comparison of the effects of different apodization functions.Therefore,this study systematically compares and analyzes the results of different types of apodization functions.Methods We build the apodization theoretical model of reflective volume Bragg grating(RVBG)based on F-matrix theory.The diffraction efficiency of different apodized volume Bragg gratings is normalized by defining effective refractive index modulation.The apodization effects of cosine,Gaussian,and secant functions are systematically compared and analyzed.An RVBG filter for the C-band is designed based on the established model,providing a theoretical design basis for

关 键 词：波分复用 光敏热折变玻璃 反射式体布拉格光栅 切趾光栅 

分 类 号：O436[机械工程—光学工程]