Simulation of Fiber Bragg Gratings Using the Transfer Matrix Method Based on MATLAB#br#
LI Qinzhe 1 ，PEI Panhu 2 ，SUN Yi 3 ，YIN Hang 4 ，HE Xuemin 4*
1．College of Chemistry and Life Sciences，Nanjing University of Posts and Telecommunications，Nanjing 210023，China;
2．College of Internet of Things，Nanjing University of Posts and Telecommunications，Nanjing 210023，China;3． College of
Artificial Intelligence，Nanjing University of Posts and Telecommunications，Nanjing 210023，China;4．College of Science，Nanjing University of Posts and Telecommunications，Nanjing 210023，China
Abstract: A virtual simulation platform for Bragg grating spectral characteristics was established based on MATLAB，employing a computational model combining the transfer matrix method and coupled-mode theory to systematically investigate the effects of parameters including chirp，grating length，modulation depth，and apodization type on reflection spectra．Simulation results demonstrate that when chirp increases from 0 nm/cm to 1．0 nm/cm，the 3 dB bandwidth of the reflection spectrum expands from 0．80 nm to 2．60 nm，representing abroadening ratio of 3．25 times．When grating length increases from 1 mm to 15 mm，peak reflectivity rises from25% to 100%，with bandwidth narrowing from 1．60 nm to 0．50 nm．As modulation depth increases from 2．0×10－4 to 2．0×10－3，peak reflectivity improves from 40% to 100%，while bandwidth extends from 0．15 nm to 1．25 nm．Apodization analysis reveals that hyperbolic tangent apodization optimizes sidelobe levels from －14 dB in uniform gratings to －32 dB． The simulation program achieves spectral calculation，depth reflection distribution，and energy accumulation visualization，quantitatively revealing that the front 30% of the grating contributes over 60% of reflection energy，with the maximum reflection rate gradient occurring at the initial section．This platform exhibits high computational accuracy and clear physical mechanisms，providing robust
technical support for Bragg grating design optimization and experimental teaching．
李沁哲 , 裴盼琥 , 孙 驿 , 尹 航 , 何学敏 . 基于 MATLAB 的布拉格光栅传输矩阵法仿真研究#br#[J]. 大学物理实验, 2026, 39(2): 101-110.
LI Qinzhe , PEI Panhu , SUN Yi , YIN Hang , HE Xuemin . Simulation of Fiber Bragg Gratings Using the Transfer Matrix Method Based on MATLAB#br#. Physical Experiment of College, 2026, 39(2): 101-110.
