Abstract: In laser angioplasty surgery, temperature sensing is of great significance for surgeons to monitor tissue temperature and control the "laser scalpel" for ablation lesion. However, existing medical sensors cannot function effectively in surgical environment with electromagnetic interference. Fiber optic Fabry-Perot (F-P) temperature sensors are expected to address this incompatibility issue in current human interventional procedures due to their advantages of high measurement accuracy, compact size, electromagnetic interference immunity, and simple structure. In this paper, we processed polydimethylsiloxane to make F-P interference cavity by laser film-forming technology, and then coated a reflective silver film on one side of the F-P interference cavity, to prepare a thin-film fiber optic F-P temperature sensor with sensitivity of 2.2375 nm/°C and linearity of 99.73%. The sensor is compact and simple in structure and low cost, and it is of great scientific significance and clinical value for the treatment of vascular diseases and even the development of overall interventional surgery.

Key words: biomedical sensing, fiber optic Fabry-Perot sensor, laser deposition technology, polydimethylsiloxane