Optimization of parameters for packaged long-period fiber grating

The micro-electromechanical systems (MEMS) process and packaging with poly-dimethylsiloxane (PDMS) polymer materials are important technologies in semiconductor industries. In this study, we propose using the L9 orthogonal array to determine the optimal parameters for an optical fiber sensor packaged with PDMS. According to analysis of variance results, the optimal parameters are as follows: a grating with a diameter of 60 μm, a period of 650 μm, and a length of 2.5 cm, as well as a photoresist structure with a width of 2 mm. The results of a large-the-best (LTB) analysis indicated that the expected sensitivity value of a sensor with those parameters would be around 0.0345 dB⁄με. After testing and verification, the sensitivity results indicated a mean sensitivity of 0.0339 dB⁄με, with the deviation in sensitivity being less than 0.14%.