Ming-Feng Chiang

All-optical router with pulse-position modulation header processing in high-speed photonic packet switching networks

In future high-speed photonic packet switching networks, it is highly desirable to carry out robust all-optical header recognition to provide high-throughput routing. The authors present a pulse-position modulation header processing (PPM-HP) scheme, offering significantly reduced routing table size and employing a single bit-wise AND operation to carry out correlation of the packet header with the entire routing table entries. The downsized routing table also offers multiple transmission modes (unicast, multicast and broadcast) in the optical layer and improves core network scalability where the number of core/edge nodes could be altered without the need for changing the number of routing table entries. The authors present modelling and simulation of the packet switching router based on PPM-HP. Noise propagation and crosstalk incurred in a multiple-hop routing scenario are investigated. The simulation results are presented and compared with the theoretical calculations.

Multiple-Hop Routing in Ultrafast All-Optical Packet Switching Network Using Multiple PPM Routing Tables

In this paper we present the modeling and simulation of multiple-hop routing in ultrafast all-optical packet switching based routers employing multiple pulse position modulation (PPM) formatted routing table. In multiple PPM routing tables (PPRTs) with reduced entry length, only a subset of the header address is converted into a PPM format in order to reduce the packet header recognition time. Packet header address correlation is carried out using only a single optical AND gate to improve the processing time. We show that the proposed scheme offers unicast/multi-cast/broadcast transmitting capabilities. The simulation results for the optical signal-to-noise ratio (OSNR) at each hop are presented and compared with the theoretical calculations.

Simulation of an all-optical 1 × 2 SMZ switch with a high contrast ratio

An all-optical 1times2 high contrast ratio (CR) switch based on the symmetric Mach-Zehnder (SMZ) interferometers is presented. Simulation results show a remarkable improvement of the inter-output CR (~25 dB) between the two outputs compared with an existing SMZ switch. It is shown that the proposed switch offers high values of inter-output CR (Gt 32dB) over a wide range of input powers using appropriate power of the control pulses.

Impact of signalwavelength on the semiconductor opticalamplifier gain uniformity for high speed optical routers employing the segmentation model

This paper investigates the impact of a train of input Gaussian pulses wavelength on semiconductor optical amplifier (SOA) gain uniformity for high speed applications. In high speed applications, the linear output gain of the input pulses is necessary in order to minimize the gain standard deviation and power penalties. A segmentation model of the SOA is demonstrated to utilize the complete rate equations. The SOA gain profile when injected with a burst of input signal is presented. A direct temporal analysis of the effect of the burst wavelength on the SOA gain and the output gain standard deviation is investigated. The output gain uniformity dependence on the input burst power and wavelength within the C-band spectrum range is analyzed. Results obtained show the proportionality of the peak-gain conditions for the SOA on the nonlinearity of the output gain achieved by the input pulses.

Characterization of the semiconductor optical amplifier for amplification and photonic switching employing the segmentation model

This paper characterizes the gain and the carrier density responses of a semiconductor optical amplifier (SOA). In order to achieve the switching functions in SOA-based optical switches, such as Symmetric Mach-Zehnder (SMZ), the effect of the input signal on the total gain response of the SOA is investigated. The theoretical operation principle is demonstrated using a segmentation model that employs the complete rate equation with third order gain coefficients. Results obtained show the input boundaries and requirements in which the SOA can be efficiently used as an amplifier and as a switch.

Ultra-fast all-optical packet-switched routing with a hybrid header address correlation Scheme

The paper presents a new node architecture for an all-optical packet router employing multiple pulse position modulation (PPM) routing table with a hybrid packet header correlation scheme. Most existing routing tables within a node contain a large number of entries, thus resulting in a long packet header address correlation time before delivering the incoming packet to its destination. In the proposed multiple PPM routing tables (PPRTs) the packet header address is based on the binary and PPM formats which leads to a much reduced routing table size. The packet header address correlation is carried out using only a single optical AND gate, thus offering reduced system complexity. It is also shown that the proposed scheme offers unicast/multi-cast/broadcast transmitting capabilities. The propose scheme is simulated and its characteristics are investigated. The output inter-channel crosstalk (CXT) of up to -18 dB and output packet power fluctuation of 2 dB have been achieved, which largely depend on the guard time between the arriving packets.

Simulations of all-optical multiple-input AND-gate based on four wave mixing in a single semiconductor optical amplifier

This paper presents the characterization and simulation of the ultrafast multiple-input AND gate exploiting the four-wave-mixing effect in a single semiconductor optical amplifier device. The on/off-contrast and amplitude-modulation ratios of the AND-gate outputs and their performances are investigated. It is shown that the proposed three-input AND gate has a large dynamic input-power range (> 20 dB) while offering on/off contrast ratio of more than 15 dB and maintaining the amplitude modulation ratio margin of 2.5 dB.

Bit Error Rate Performance of Multiple-Channel OTDM Demultiplexer Employing A Chained Symmetric Mach-Zehnder Switch

This paper presents a high-speed multiple-channel optical time division multiplexed (OTDM) demultiplexer based on a chained symmetric Mach-Zehnder (CSMZ) switch. In CSMZ switch semiconductor optical amplifier (SOA) are shared between two chained arms in contrast to the MZ based multiple-channel demultiplexers where there is an SOA in each arm. The analysis for bit error rate (BER) and the average received power penalty is presented and the results are compared with the simulated data. It is shown that the power penalty incurred is highly dependent on the value of coupling ratio and the channel number.