Jiun-Shiou Deng

Equivalent circuit model of quantum-well lasers

A study of equivalent circuit model of quantum well lasers derived from quantum well rate equation has been carried out. Pulse response simulation results obtained from a SPICE simulator indicates that various modulation properties, e.g., turn-on delay, relaxation oscillation frequency, and on/off aspect ratio, have a substantially different behavior than those of DH lasers. This model offers a fundamental building block for the simulation of the over all signal transmission when using quantum-well lasers as a light source. >

Double-layer networks with holographic optical switches

The double-layer networks have the advantages of being strictly nonblocking and having a simpler routing algorithm, the lowest system insertion loss, a zero differential loss, fewer drivers, fewer interconnection lines, fewer crossovers, and the best signal-to-noise-ratio characteristic compared with any nondilated network. Using holographic optical switches to construct these networks not only eliminates all interconnection lines and crossovers but also reduces the number of drivers.

A strictly nonblocking network based on nonblocking 4 × 4 optical switches

Abstract Recently, the demand for communication has been growing rapidly. Hence, optical multistage network technologies are more appreciated nowadays. A double-layer network is a strictly nonblocking network, and it has the lowest system insertion loss of non-dilated networks. A Benes network is a rearrangeably nonblocking network, and it has the same system insertion loss as a double-layer network. We have proposed the use of modified polarization selection elements (PSEs). The system insertion loss, number of drivers, and number of required components of a double-layer network could be reduced if it is constructed with modified PSEs. A nonblocking 4×4 optical switch with two stages of polarization selective elements has been presented in our previous study. Based on this nonblocking 4×4 optical switch, we propose a strictly nonblocking network structure which features even lower system insertion loss than those of a double-layer network and a Benes network. The signal-to-noise ratio of the proposed network structure is a constant, and is higher than the constraint, although it is lower than that of the double-layer network. The number of major components of the proposed network is less than that of a double-layer network and larger than that of a Benes network, since a Benes network is rearrangeably nonblocking. We also offer a routing algorithm for the new proposed network; the time complexity of the routing algorithm is O ( 1 ) .

Cyclic crossbar network for photonic switching

Feature Issue on Optical Interconnection Networks (OIN). The rectangular crossbar network is commonly used in switching networks because it has the advantages of easy connection-path rebuilding, wide-sense nonblocking, and no crossover in its interconnection lines. However, this kind of network has two major disadvantages: one is that it has nonzero differential loss, and the other is that its signal-to-noise ratio (SNR) is decreased by both the increase of the network dimension and the insertion loss of switches. Here the cyclic crossbar network structure is presented. The cyclic crossbar network is similar to the rectangular crossbar network. For both types of network, an N×N network is constructed by N columns, and each column consists of N switches. The major difference is that construction with N backslash lines and N slash lines is used for the cyclic crossbar network. For every backslash line to have its crosspoint on the right side, the network structure is designed into a circle shape. In this type of network, the differential loss is eliminated and SNR is independent on insertion loss of switches, but the original advantages are maintained.

Component Reducing and Routing Algorithm of Double-Layer Network with Rearranging the Channel Allocation

Recently, there has been a growing demand for communication systems. The implementation of optical multistage interconnection networks (MINs) is more and more noticed. In our previous study, we have presented a modified version of holographic optical switches (HOSs). The double-layer network constructed by the modified version of HOSs and rearranged the channels allocation, the number of electro-optic halfwave plates (EOHWPs) could be significantly decreased from 2N^2-2N to 2Nlog2N. We propose a routing algorithm for the novel DLN and the time complexity of the routing algorithm is O (1).

Multicast Network with MMI-Based Optical Switches on Active Splitter/Active Combiner Structure

Multicast communications have become more and more important recently, especially in their applications in multimedia communication, quality of service (QoS), video conferencing, and distance education. In a point-to-point (PTP) optical communication system, how to provide multicast services is an essential issue. There are some advantages of active splitter/active combiner (AS/AC) networks, such as strictly nonblocking, simpler routing algorithm, lower system-insertion-loss, zero differential loss, and better signal-to-noise characteristics. The active multimode interference (MMI) coupler can provide splitting/combining operations with low loss and good balancing. It has been demonstrated that the AS/AC network constructed by active MMI switching devices can implement the multicast and PTP communications simultaneously. In this study, we offer two multicast algorithms, parallel multicast, and tunable multicast, on AS/AC network. The parallel multicast algorithm is suitable when there are multi requests arriving at the same time. The tunable multicast algorithm is suitable for balancing the output signals’ power.