In our research we develop a fiber dispersion compensation module based on higher-order modes By using higher order modes we can obtain smaller nonlinear effect tailorable dispersion curve therefore this module is very compatible with the high power laser module The key components of this module are the mode converter and a well-designed dispersion compensation fiber By using long period grating (LPG) designing the coupling region of a resonant mode converter to the half of the beat length we can achieve total power mode conversion This kind of mode converter is easier to fabricate but having less error tolerance and narrow bandwidth Recently the analogies between quantum theory and waveguide optics has been investigated From this we can develop the mode converter with better error tolerance through adiabatic theory which has been used in the quantum control For the adiabatic following mode converter the device length must be long enough to satisfy the adiabatic condition We can add the counter-diabatic term into the mode converter design to get the improvement but it requires an extra step in fabrication Therefore we introduce the rotation method of Hamiltonain to simplify the fabrication process into one step For dispersion compensation we propose to use the fiber with core-ring-trench structure to get the tailarable dispersion curve in the LP02 mode We develop a finite-difference-based numerical tool to design and analyze these kinds of fibers
Mode converter for higher order mode fiber dispersion compensation using shortcut to adibaticity
驥之, 陳. (Author). 2014 8月 21
學生論文: Master's Thesis