Reflective Long Period Grating Based Temperature Sensor
We experimentally demonstrate a reflective long period grating based temperature sensor with a temperature sensitivity coefficient of 0.046 nm/°C in the range between 23°C and 200°C. Compared to traditional metal coating methods, such as evaporation, we used a cost-effective brush coating method to coat silver on both the end facet and a 60cm long tail end of the fiber beyond a long period grating (LPG) to realize a reflection mode LPG. The measured optical spectrum of the fabricated reflective LPG completely mimics the transmitted spectrum with reduced intensity. This cost-effective method for coating metal will pave the way for inexpensive LPG and other optical fiber sensor manufacturing and widespread utilization.
Rana, Sohel; Kandadai, Nirmala; and Subbaraman, Harish. (2021). "Reflective Long Period Grating Based Temperature Sensor". Proceedings of SPIE, 1168219. https://doi.org/10.1117/12.2576989