Apodized long period grating and sensitivity analysis of high order resonant wavelengths for temperature measurement

An apodized Long Period Grating (LPG) is presented to compute and depict the temperature sensitivity for different resonant wavelengths in the transmission spectrum. The spectrum often gets distorted due to overlapping of multiple modes and appearance of large quantity side lobes as a result of the impacts of higher order period. Therefore, the introduction of apodization profile is necessary to obtain the proper shape of the spectrum by preventing any distortions. It has been noted that the higher order mode (LP07) shows greater temperature sensitivity with 0.043 nm/o C as compared with the lower order modes (i.e., LP04, LP05, LP06) for 100-600 degrees C. Different Machine Learning models are implemented for the predictive analysis of resonant wavelength changes in accordance with the temperature effects for enhancing the effectiveness of the sensor response. This approach is highly desirable in various applications by ensuring the safety, efficiency and reliability of the LPG-based sensing outcomes.