Design of hollow-core photonic band-gap fibers for CH4 and C2H2 optical fiber sensors
A hollow-core photonic band-gap fiber for optical fiber sensors is designed. According to the calculation, we get the parameters of the photonic band-gap fiber as d=0.94∗2.60μm, R=Λ=2.60μm for C<inf>2</inf>H<inf>2</inf>, and d=0.94∗2.41μm, R=Λ=2.41μm for CH<inf>4</inf>. Around the wavelength of λ<inf>C2H2</inf> = 1.53μm and λ<inf>CH4</inf> = 1.66 μm, 98% of the energy is propagated in the core, the fiber is suitable to be used to detect the gas such as CH<inf>4</inf> and C<inf>2</inf>H<inf>2</inf>.