Nuclear fusion is a clean and virtually inexhaustible source of energy and is currently humanity's hope for meeting its future energy needs. One promising method for obtaining energy from nuclear fusion is magnetic confinement of hot plasmas by strong magnetic fields. Of the various nuclear fusion reactor concepts, compact spherical tokamaks are the most advanced, achieving the highest power densities. The recent development of high-temperature superconductors (HTS), which can operate at 20 K in magnetic fields of up to 20 T with high current densities (up to 400 A/mm²), has transformed the international nuclear fusion landscape. This development paves the way for even more compact, efficient and economical fusion reactors. Cryogenic magnets in general, and HTS magnets in particular are complex and expensive systems, and In general, cryogenic magnets, and HTS magnets in particular, are complex and expensive systems. Therefore, it is imperative that they are protected against accidental damage during operation. Magnets are susceptible to quench events, whereby a region of the coil ceases to be superconducting, causing the current to encounter non-zero resistance. This transition leads to rapid local heating that could potentially cause catastrophic damage to the system. Therefore, reliable quench detection with advanced monitoring strategies is critical to ensuring the structural integrity of the magnets and stable reactor operation, which is required to maintain plasma confinement conditions. Conventional quench detection techniques based on electrical and thermal measurements are well established for low-temperature superconductors (LTS) systems. However, they are less effective in HTS systems due to slower quench propagation, smaller voltage signals and the delayed response of point-based thermal sensors. These challenges highlight the need for more sensitive, distributed monitoring solutions, such as fibre Bragg grating (FBG)-based optical sensing systems. Compared with conventional electrothermal sensors, FBG sensors offer several advantages, including immunity to electromagnetic interference, the ability to multiplex, and minimal thermal perturbation. This study explores the integration of an FBG-based fibre optic sensor network into HTS tapes for real-time temperature monitoring and quench detection in tokamak reactors. Owing to the limited space available for sensor integration within HTS tapes, the effect of reducing the fibre coating thickness on FBG sensitivity at a cryogenic temperature of 20Kk was studied experimentally at a laboratory scale prior to Tokamak integration, with the aim of minimizing the coating thickness without compromising performance.