Making use of this expression to calculate the phase grating in high resolution image simulation can greatly reduce the calculating time. In this paper, the derivation of the expression is introduced, and then the com...Making use of this expression to calculate the phase grating in high resolution image simulation can greatly reduce the calculating time. In this paper, the derivation of the expression is introduced, and then the computer routine is explained in details. Finally the potential projection map of Mg44Rh7 along [001] direction is shown as an illustration. All operations are carried out in real space, so we call the calculation method as the real space method.展开更多
In this Letter,we demonstrate a 1×4 low-crosstalk silicon photonics cascaded arrayed waveguide grating,which is fabricated on a silicon-on-insulator wafer with a 220-nm-thick top silicon layer and a 2μm buried o...In this Letter,we demonstrate a 1×4 low-crosstalk silicon photonics cascaded arrayed waveguide grating,which is fabricated on a silicon-on-insulator wafer with a 220-nm-thick top silicon layer and a 2μm buried oxide layer.The measured on-chip transmission loss of this cascaded arrayed waveguide grating is～4.0 dB,and the fiber-towaveguide coupling loss is 1.8 dB/facet.The measured channel spacing is 6.4 nm.The adjacent crosstalk by characterization is very low,only -33.2 dB.Compared to the normal single silicon photonics arrayed waveguide grating with a crosstalk of ～-12.5 dB,the crosstalk of more than 20 dB is dramatically improved in this cascaded device.展开更多
The characteristic modifications are reported on the surface of polymeric waveguide film in the process of vol- ume-grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200...The characteristic modifications are reported on the surface of polymeric waveguide film in the process of vol- ume-grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200 fs and wavelength of 800 nm is focused normal to the surface of the sample. The surface morphology modifications are as- cribed to a fact that surface swelling occurs during the process. Periodic micro-structure is inscribed with increasing incident power. The laser-induced swelling threshold on the grating, which is higher than that of two-photon initiated photo-polymerization （TPIP） （8 mW）, is verified to be about 20 mW. It is feasible to enhance the surface smoothness of integrated optics devices for further encapsulation. The variation of modulation depth is studied for different values of incident power and scan spacing. Ablation accompanied with surface swelling appears when the power is higher. By ootimizing the laser carvinR oararneters, hizhly efficient grating devices can be fabricated.展开更多
A 45-channel 100 GHz arrayed waveguide grating(AWG) based on Si nanowire waveguides is designed, simulated and fabricated. Transfer function method is used in the spectrum simulation. The simulated results show that t...A 45-channel 100 GHz arrayed waveguide grating(AWG) based on Si nanowire waveguides is designed, simulated and fabricated. Transfer function method is used in the spectrum simulation. The simulated results show that the central wavelength and channel spacing are 1 562.1 nm and 0.8 nm, respectively, which are in accord with the designed values, and the crosstalk is about-23 dB. The device is fabricated on silicon-on-insulator(SOI) substrate by deep ultraviolet lithography(DUV) and inductively coupled plasma(ICP) etching technologies. The 45-channel 100 GHz AWG exhibits insertion loss of 6.5 dB and crosstalk of-8 dB.展开更多
文摘Making use of this expression to calculate the phase grating in high resolution image simulation can greatly reduce the calculating time. In this paper, the derivation of the expression is introduced, and then the computer routine is explained in details. Finally the potential projection map of Mg44Rh7 along [001] direction is shown as an illustration. All operations are carried out in real space, so we call the calculation method as the real space method.
基金partially supported by the National Natural Science Foundation of China under Grant Nos.61674072,61565011,and 51304097
文摘In this Letter,we demonstrate a 1×4 low-crosstalk silicon photonics cascaded arrayed waveguide grating,which is fabricated on a silicon-on-insulator wafer with a 220-nm-thick top silicon layer and a 2μm buried oxide layer.The measured on-chip transmission loss of this cascaded arrayed waveguide grating is～4.0 dB,and the fiber-towaveguide coupling loss is 1.8 dB/facet.The measured channel spacing is 6.4 nm.The adjacent crosstalk by characterization is very low,only -33.2 dB.Compared to the normal single silicon photonics arrayed waveguide grating with a crosstalk of ～-12.5 dB,the crosstalk of more than 20 dB is dramatically improved in this cascaded device.
基金supported by the National Natural Science Foundation of China/the Research Grants Council of Hong Kong Joint Research Scheme a grant for NSFC/RGC(No.50218001)the National Science Foundation of China(No.50173015)
文摘The characteristic modifications are reported on the surface of polymeric waveguide film in the process of vol- ume-grating fabrication. The light from a mode-locked 76 MHz femtosecond laser with pulse duration of 200 fs and wavelength of 800 nm is focused normal to the surface of the sample. The surface morphology modifications are as- cribed to a fact that surface swelling occurs during the process. Periodic micro-structure is inscribed with increasing incident power. The laser-induced swelling threshold on the grating, which is higher than that of two-photon initiated photo-polymerization （TPIP） （8 mW）, is verified to be about 20 mW. It is feasible to enhance the surface smoothness of integrated optics devices for further encapsulation. The variation of modulation depth is studied for different values of incident power and scan spacing. Ablation accompanied with surface swelling appears when the power is higher. By ootimizing the laser carvinR oararneters, hizhly efficient grating devices can be fabricated.
基金supported by the National High Technology Research and Development Program of China(No.2015AA016902)the National Natural Science Foundation of China(Nos.61435013 and 61405188)
文摘A 45-channel 100 GHz arrayed waveguide grating(AWG) based on Si nanowire waveguides is designed, simulated and fabricated. Transfer function method is used in the spectrum simulation. The simulated results show that the central wavelength and channel spacing are 1 562.1 nm and 0.8 nm, respectively, which are in accord with the designed values, and the crosstalk is about-23 dB. The device is fabricated on silicon-on-insulator(SOI) substrate by deep ultraviolet lithography(DUV) and inductively coupled plasma(ICP) etching technologies. The 45-channel 100 GHz AWG exhibits insertion loss of 6.5 dB and crosstalk of-8 dB.
