A novel and simple polarization independent grating couplers is designed and analyzed here, in which the TE polarization and the TM polarization light can be simultaneously coupled into a silicon waveguide along the s...A novel and simple polarization independent grating couplers is designed and analyzed here, in which the TE polarization and the TM polarization light can be simultaneously coupled into a silicon waveguide along the same direction with high coupling efficiency. For the polarization-insensitive grating coupler, the coupling effi- ciencies of two orthogonal polarizations light are more than 60% at 1550 nm wavelength based on our optimized design parameters including grating period, etching height, filling factor, and so on. For TE mode the maximum efficiency is ~72% with more than 30 nm i dB bandwidth, simultaneously, for TM mode the maximum efficiency is 75.15% with 40 nm 1 dB bandwidth. Their corresponding wavelength difference between two polarizations＇ coupling peaks is demonstrated to be 35 nm. Polarization independent grating coupler designed here can be widelv used in optical communication and ontical information processing.展开更多
An integrated, tunable spectrometer based on a silicon-on-sapphire platform is designed at wavelengths of 2.29-2.35 μm. Its pivotal component is a 4.7 μm-radius ring resonator on a graphene monolayer. Its full width...An integrated, tunable spectrometer based on a silicon-on-sapphire platform is designed at wavelengths of 2.29-2.35 μm. Its pivotal component is a 4.7 μm-radius ring resonator on a graphene monolayer. Its full width at half-maximum and free spectral range are ~1.5 and ~45 nm, respectively, as found through a numerical simulation and theoretical computation. Sixteen characteristic peaks are obtained by tuning the Fermi level of graphene. The gap between the ring and waveguides is increased by 0.5 μm to increase the resolution, and though this can drastically reduce the transmission rate, an upper sapphire layer maintains light to the drop port.展开更多
基金supported by the National Natural Science Foundation of China(No.60907003)the Foundation of NUDT(No.JC13-02-13)+1 种基金the Hunan Provincial Natural Science Foundation of China(No.13JJ3001)the Program for New Century Excellent Talents in University(No.NCET-12-0142)
文摘A novel and simple polarization independent grating couplers is designed and analyzed here, in which the TE polarization and the TM polarization light can be simultaneously coupled into a silicon waveguide along the same direction with high coupling efficiency. For the polarization-insensitive grating coupler, the coupling effi- ciencies of two orthogonal polarizations light are more than 60% at 1550 nm wavelength based on our optimized design parameters including grating period, etching height, filling factor, and so on. For TE mode the maximum efficiency is ~72% with more than 30 nm i dB bandwidth, simultaneously, for TM mode the maximum efficiency is 75.15% with 40 nm 1 dB bandwidth. Their corresponding wavelength difference between two polarizations＇ coupling peaks is demonstrated to be 35 nm. Polarization independent grating coupler designed here can be widelv used in optical communication and ontical information processing.
基金supported by the Advanced Research Program of National University of Defense Technology(Nos.JC13-02-15 and JC13-02-13)the Natural Science Foundation of Hunan Province(Nos.13JJ4008 and13JJ3001)the Program for New Century Excellent Talents in University(No.NCET-12-0142)
文摘An integrated, tunable spectrometer based on a silicon-on-sapphire platform is designed at wavelengths of 2.29-2.35 μm. Its pivotal component is a 4.7 μm-radius ring resonator on a graphene monolayer. Its full width at half-maximum and free spectral range are ~1.5 and ~45 nm, respectively, as found through a numerical simulation and theoretical computation. Sixteen characteristic peaks are obtained by tuning the Fermi level of graphene. The gap between the ring and waveguides is increased by 0.5 μm to increase the resolution, and though this can drastically reduce the transmission rate, an upper sapphire layer maintains light to the drop port.
