Tunable slow light and buffer capability in photonic crystal coupled-cavity waveguides based on electro-optic effect

An enhanced photonic crystal coupled-cavity waveguide (PC-CCW) is proposed to realize compact, ultra-fast modulated and high-performance buffering application. The slow light and buffer performances of PC-CCW are optimized by adjusting the cavity spacing and the hole size around the cavity. In the optimized structure, the group velocity is below 2.713 × 10− 4c. The corresponding delay time, buffer capacity and Q factor can reach as high as 12.286 ns, 68.5 bit and 3525, respectively. Then the dynamic modulation of slow light transmission and buffer capacity in PC-CCW are systemically studied. The simulation shows that the buffer capacity and the physical size of each bit are unchanged as the applied voltage increases. While the wavelength shift and delay time decrease almost linearly as the applied voltage increases. And the modulation sensitivities are about 3.726 nm/mV and 0.875 ns/mV, respectively. The Q factor also decreases accordingly.