Modeling of Fano Resonance in High-Contrast Resonant Grating Structures

A new model is presented for Fano resonance in resonant grating structure based on the temporal coupled mode theory. By using this model, the reflection spectrum can be reproduced with the information of eigenmode of the structure, which can be numerically calculated by the finite element method. Therefore, the eigenmode plays a key role in determining the profile of the line shape of the Fano resonance in the resonant grating structure. When the space of two grating modulations is decreased, the line shape experiences a significant change. Such a drastic change can be attributed to the increase of quality factor of the eigenmodes. Thus, our model not only provides a simple and intuitive understanding on the mechanism of Fano resonance, but it also offers a convenient way to engineer the line shape of the Fano resonance. The proposed model can be used in many applications, such as biosensors, optical filters, and optical switchers.

A new burst assembly technique for supporting QoS in optical burst switching networks

This letter proposes a new burst assembly technique for supporting QoS in optical burst switching (OBS) networks. It consists of the adaptive-threshold burst assembly mechanism and QoS-based random offset-time scheme. The assembly mechanism, which is fit well to multi-class burst assembly, not only matches with IP QoS mechanism based on packet classification, and also utilizes fairly and efficiently assembly capacity. Based on token-bucket model and burst segment selective discard (BSSD), the offset-time scheme can smooth the traffic to support OBS QoS. The simulation results show that the technique can improve the performance in terms of packet loss probability (PLP).

A scheme of optical interconnection for super high speed parallel computer

An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.

Co-existence generation of XG-PON and single carrier XLG-PON for ultra-high definition TV transmission with entirely passive optical plant

International telecommunication union (ITU) recently has standardized ultra-high definition television (UHD-TV) with a resolution which is 16 times more than that of current high definition TV. Increasing the efficiency of video source coding or the capacity of transmission channels will be needed to deliver such programs by passive optical network (PON). In this paper, a complete passive co-existence of 10 Gbit-PON (XG-PON) and single carrier 40 Gbit-PON (XLG-PON) for overlay of UHD-TV distribution to 32 optical network units (ONUs) on broadcast basis is presented. The results show error free transmission performance with negligible power penalty over a 20 km bidirectional fiber.

Linearized wideband and multi-carrier link based on TL-ANN

The analog photonics link(APL) is widely used in microwave photonics. However, in wideband and multi-carrier systems, the third inter-modulation distortion(IMD3) and cross-modulation distortion(XMD) will jointly limit the spurious-free dynamic range(SFDR) of links. In this paper, we experimentally present a linearized wideband and multi-carrier APL, in which the IMD3 and XMD are mitigated simultaneously by using artificial neural networks with transfer learning(TL-ANN). In this experiment, with different artificial neural networks, which are trained with the knowledge obtained from the two-or three-sub-carrier system, the IMD3 and XMD are suppressed by 21.71 d B and 11.11 d B or 22.38 d B and 16.73 d B, and the SFDR is improved by 13.4 d B or 14.3 d B, respectively. Meanwhile, compared with previous studies, this method could reduce the training time and training epochs to 16% and 25%.

Realization of quantum efficiency enhanced PIN photodetector by assembling resonant waveguide grating

We demonstrate an InP/InGaAs PIN photodetector with enhanced quantum efficiency by assembling silicon resonant waveguide gratings for the application of polarization sensitive systems. The measured results show that quantum efficiency of the photodetector with silicon resonant waveguide gratings can be increased by 31.6% compared with that without silicon resonant waveguide gratings at the wavelength range of 1500 to 1600 nm for TE-polarization.

High-speed modified uni-traveling-carrier photodiode with a new absorber design

The Gaussian doping is used to optimize the performance of InP/InGaAs uni-traveling-carrier photodi ode （UTC-PD） in this letter. The UTC-PD structure is modeled with drift-diffusion approach and the comparisons of the characteristics for four UTC-PDs with different doping schemes in absorption layer are made. According to the comparison, one optimized UTC-PD where the InP collection layer is partly replaced by a depleted InGaAs using Gaussian doping on top of lightly constant background doping in the absorption layer is presented, with f3dn of 79 GHz, which is more than 1.9 times higher than that with the constant doping in the absorption layer.