Design Of Metal-filled Photonic Crystal Fiber And Experimental Study On Femtosecond Laser Transmission

Due to the unique structure and diversified material of photonic crystal fibers,they possess many excellent optical properties that traditional fibers don't have,such as large mode area,high birefringence characteristics,non cut-off single mode transmission and strong nonlinearity.In recent years,researchers develop a great interest in producing Miniaturized and lightweight optoelectronic devices by utilizing the excellent optical properties of PCF,Metal-filled photonic crystal fiber sets surface plasmon effect and flexible structure design in one,which can further enhance the performance of photonic crystal fiber,it provides a new opportunity for the development of new photonic devices.In this paper,two kinds of gold-coated photonic crystal fibers are designed.The femtosecond laser transmission test was carried out on the homemade silver-coated photonic crystal fiber,the main contents are as follows:Firstly,a kind of gold-coated PCF filter based on surface plasmon theory is designed.By filling gold film in two air holes,the performance of the filter is greatly improved through using the resonance coupled between defect plasma mode and the core mode.The transmission characteristics of the polarization filter are analyzed,discovered that the proposed PCF can work at two communication bands.Secondly,based on the mode coupling theory,a kind of polarization splitter based on dual-core photonic crystal fiber with gold-coated air hole is designed.The mode coupling is enhanced between the two cores through filling gold film in centre air hole,the effect of gold and coupling characteristics are analyzed.In the low-loss window of optical communication,only a micron-order length is needed to achieve a good polarization splitting effect.Finally,an experimental platform of testing femtosecond laser Transmission is built.Silver filled PCF and highly nonlinear PCF are tested for femtosecond laser transmission characteristics.Spectral broadening is observed for both PCF experimentally.The variation of optical pulse broadening with wavelength and power is studied.