Research Of Dispersion And Nonlinearity On Photonic Crystal Fiber

These research works of this dissertation are supported by National Basic Research Program of China (No.2003CB314900), the Key Grant Project of Chinese Ministry of Education (No. 104046).Photonic crystal fiber (PCF) is also named microstructure fiber, the design of PCF's structure is flexible. It has many unusual properties, such as endless single mode propagation, flexible and controllable mode fields, controllable dispersion properties etc. These properties make that PCF has already found capacious application foreground in the field of optical communication. PCF can be used for bandwidth expansion, dispersion compensation, all-optical switch and generation of super-continuous spectrum etc. In this thesis, the theoretical and experimental research of dispersion and nonlinearity is discussed in detail, the main contents and innovations are listed as follows:1. Photonic crystal fibers (PCF) with different structural parameters are theoretically analyzed using beam propagation method. According to the formula of dispersion coefficient D, effective mode area A_eff and nonlinear coefficientγ, I make use of MATLAB and R-SOFT software emulating the structure of PCF, analyze the relationship between D,γand pitch∧, hole diameter d. Via adjusting the structure parameter constantly, I have designed a novel high nonlinear,broadband dispersion flatten PCF. In the wavelength variety range of near 300nm (1300-1600nm), PCF's dispersion value is at +0.8～-2.4 (ps/km·nm), non-linear coefficient is above 20(1/w·km).2. I have participated in validating experiments of optical switching based on PCF, obtained extinction rate is 21.38dB, without signal light path polarization control apparatus, insertion loss is 4.77dB, with signal light path polarization control apparatus, insertion loss is 6.05dB.3. I have participated in validating experiments of broadband dispersion compensating based on PCF. At the wavelength of 1550nm, PCF can compensate G.652 fiber's dispersion correspondence of 70 times length of itself. At the condition of compensating completely in the wavelength of 1550nm, in the range of 120nm (1520-1640nm) , utilized the PCF compensate G.652 fiber's dispersion correspondence of 70 times length of itself Residual dispersion rate is -2%⁶%.