Investigation of temperature sensing characteristics in selectively infiltrated photonic crystal fiber.

In this paper, we investigate and experimentally demonstrate the influences of distance between the silica core and the glycerin core of a selectively glycerin-infiltrated photonic crystal fiber (PCF) on the mode characteristics, as well as the temperature sensitivity. By comparing the simulation and experiment results of three single-void glycerin-infiltrated PCFs with the glycerin core being one period, two periods and three periods away from the silica core respectively, it reveals that the smaller distance between the silica core and the glycerin core does not affect the modes indices, but increases the intensities of modes in the glycerin core and thus enhances the temperature sensitivity. Consequently, the temperature sensitivity can be controlled and tuned by appropriately designing the structure parameters of glycerin-infiltrated PCF. Besides, the highest temperature sensitivity up to -3.06nm/°C is obtained in the experiment as the glycerin core is nearest to the silica core. This work provides insights into the design and optimization of the liquid-infiltrated PCF for sensing applications.