The aerospace industry increasingly adopts thermoplastic composites for lightweight and sustainable aerostructures. Ensuring joint integrity demands advanced sensing for process control and Structural Health Monitoring (SHM). The EU-funded PLEIADES project develops an integrated photonic sensing solution for automated induction welding of composite joints, enabling precise real-time thermal control. We present the simulation, design, and evaluation results of bragg grating based silicon photonic PIC-based temperature and strain sensors with efficiencies of 72 pm/°C and 1 pm/με, at a 4 kHz monitoring rate, in a temperature and strain decoupling architecture. Furthermore, their small footprint (δ < 1.5 mm²), enabling high spatial resolution monitoring, crucial for detecting localized defects within the weld area without compromising joint quality or the structural integrity of the produced part.
