Abstract
In this study, the hollow-core photonic crystal fiber (HC-PCF) optical switching effect in liquid nitrogen (LN2) environment is demonstrated and experimentally investigated. Turning off the light transmission is realized by the liquefaction of air present in the airholes of the HC-PCF when the fiber is immersed in LN2, and turning on the light transmission is realized by the evaporation of air when the fiber is taken out of LN2. The extinction ratio of the optical switching effect is found to be ∼50 dB; furthermore, the turn-on and turn-off time of the optical switching effect can reach ∼8 s and ∼3 s, respectively. Thus, optical switching effect in a HC-PCF in LN2 environment can be easily realized, which is beneficial in building all-fiber in-line low-frequency optical-switching systems that can be potentially applied in areas such as fiber sensors.
Highlights
Photonic crystal fibers (PCF) have been used to realize various functions based on different optical effects by employing their flexible airhole structures and the special wave-guiding mechanism [1], [2]
For hollow-core photonic crystal fibers (HC-PCF), the optical switching effect cannot be realized using this method, because it guides light based on the photonic bandgap (PBG) effect which location and range are influenced when the refractive index of airholes are changed by the filling materials [14], [15]
Experimental Study HC-PCF Optical Switching Effect is placed beside the HC-PCF to monitor the temperature. Both the adapters are placed in a sealed container, and a pump connected with this sealed container is used to regulate the air pressure within the HC-PCF, because the butt-coupling makes airholes of the HC-PCF keep open in the sealed container
Summary
Photonic crystal fibers (PCF) have been used to realize various functions based on different optical effects by employing their flexible airhole structures and the special wave-guiding mechanism [1], [2]. To realize the optical switching effect in a solid-core photonic crystal fibers (SC-PCF), a common method is to fill the airholes of SC-PCF with different materials, such as liquid crystals [4], [5], organic compounds [6]–[9], and nanoparticle-doped mixtures [10], and tune the fiber loss by changing the refractive index of the filling material, which depends on temperature [11]–[13]. For hollow-core photonic crystal fibers (HC-PCF), the optical switching effect cannot be realized using this method, because it guides light based on the photonic bandgap (PBG) effect which location and range are influenced when the refractive index of airholes are changed by the filling materials [14], [15]. When the pressure in the airholes is 1 atm, the extinction ratio (ER) of the optical switching effect is ∼50 dB, and the turn-on and turn-off time reaches ∼8 s and ∼3 s, respectively
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
