| Summary: | 碩士 === 國立成功大學 === 機械工程學系 === 102 === In this research a series of tunable photonic crystal (PhC) devices are proposed. The magneto-optical (MO) materials are infiltrated into the PhC structure to become point or line defects. With out-of-plane magnetization, the degenerate resonant modes splits into two counter-rotating modes at different frequencies. Furthermore, the quality factor of two splitting modes significantly increases to about 4000, which is suitable for applications of dense wavelength-division-multiplexing (DWDM) systems and refractive index sensors. When the out-of-plane magnetization is applied to the MO line defects in the PhCs, the fundamental waveguide mode vanishes in specific frequency region. This phenomenon causes the fundamental mode waves blocked by the PhC structure. Based on the effect, the power can be switched by applying external magnetic fields. When two MO line defects are put side by side in the PhC structure with opposite direction of magnetization, the time-reversal and space inversion symmetries breaks, which causes the difference of the dispersion curves for opposite propagating directions. Using this effect a PhC diode can be achieved. Computations are performed using plane wave expansion (PWE) and finite difference time domain (FDTD) method.
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