All-Optical Label Extractor/Eraser for In-Band Labels and 160-Gb/s Payload Based on Microring Resonators

Photonic integration of an all-optical packet switch (AOPS) is a crucial issue since it leads to a great reduction of volume, power consumption, and costs. Recently, a 1 times 4 AOPS was successfully demonstrated by using an all-optical label extractor/eraser. The label extractor/eraser was implemented by means of fiber Bragg gratings and optical circulators that prevent the photonic integration of the AOPS. Here, we demonstrate a passive and asynchronous photonic integrated all-optical label extractor/eraser by using narrowband silicon-nitride add-drop ring-resonators. By exploiting the narrow bandwidth of the drop port and pass-through port error-free simultaneous separation/erasing of the in-band labels from the 160-Gb/s packet payload was demonstrated without noticeable pulse-shape distortions.     

Simultaneous Data Regeneration and Digital Label Swapping in an SOA-MZI Device

We demonstrate all-optical regeneration of a 10-Gb/s data stream, with bit-error-rate improvement, simultaneously with digital label swapping, in a monolithically integrated semiconductor optical amplifier Mach–Zehnder interferometer device.      

All-Optical Data Vortex Node Using an MZI-SOA Switch Array

We propose and demonstrate a new structure of a Data Vortex switch node for all-optical routing of wavelength-division-multiplexing (WDM) 10-Gb/s optical packets. The proposed node consists of two Mach-Zehnder interferometers with integrated semiconductor optical amplifier: an optical and gate and a high-speed optical switch. In the experiment, WDM 10-Gb/s data packets are successfully routed with 1-dB power penalty at a bit-error rate of 10^-9.     

All-Optical Label/Payload Separation at 40 Gb/s

We demonstrate an all-optical label/payload separation circuit implemented with hybridly integrated semiconductor-optical-amplifier-based Mach–Zehnder switches. It is shown to operate error-free with 40-Gb/s variable length data packets containing$2 ^7-1$pseudorandom bit sequence and short guardbands between them. The circuit requires only the data packets as input and its complexity does not increase with label length.     

All-Optical Four-Wavelength Burst Mode Regeneration Using Integrated Quad SOA-MZI Arrays

We demonstrate an all-optical four-wavelength 3R burst mode regenerator, operating error-free with 10-Gb/s variable length data packets that exhibit 6-dB packet-to-packet power variation. The circuit was implemented using a sequence of three integrated quadruple semiconductor optical amplifier-based Mach–Zehnder interferomentric arrays.      

Payload-envelope detection and label-detection integrated photonic circuit for asynchronous variable-length optical-packet switching with 40-gb/s RZ payloads and 10-gb/s NRZ labels

A photonic integrated circuit that performs 40-Gb/s payload-envelope detection (PED) and 10-Gb/s label detection for asynchronous variable-length optical-packet switching is demonstrated. The circuit consists of an InP photonic integrated device combined with electronic GaAs and InP devices on a carrier. Asynchronous variable-length optical packets with 40-Gb/s return-to-zero (RZ) payloads and 10-Gb/s non-RZ (NRZ) labels are processed by the circuit. The circuit outputs a PED electrical signal that represents the temporal location of the payload and a 10-Gb/s electrical signal representing the optical label. The optical label is detected error free. The PED signal has a rise/fall time of 3-ns and 150-ps jitter. The PED signal was also used to erase and rewrite the optical labels error free.     

A novel scheme for generating optical dark return-to-zero pulses and its application in a label switching optical network

We experimentally demonstrate a novel and simple method to generate a dark return-to-zero (RZ) pulse with tunable pulsewidth and extinction ratio by using a dual-arm LiNbO /sub 3/ intensity modulator. Our experimental results show that this dark RZ pulse signal can be used in a 10-Gb/s optical packet switching system as an optical label. In addition, we demonstrate that this dark RZ label can be easily erased using the gain saturation effect in a semiconductor optical amplifier.     

40-Gb/s 3R Burst Mode Regenerator Using Four Integrated MZI Switches

We demonstrate an all-optical 3R burst mode regenerator operating error-free with 40-Gb/s data packets. It is comprised of a sequence of four hybridly integrated semiconductor optical amplifier Mach-Zehnder interferometric switches and is shown to operate with short, variable length and asynchronous data packets, with a dynamic range of 9.3 dB     

Design of All-Optical Contention Detection and Resolution for 40-Gb/s Label-Switched Routers

We present a new scheme for all-optical contention detection and time-domain contention resolution of optical packets in label-switched routers that employ all-optical label recognition. The contention detection subsystem provides all the necessary control signals required to drive an optically controlled buffer which employs 1 times 2 optical switching elements and an optical fiber delay line. The state of the buffer is dynamically controlled on a per-packet basis with all the decisions and processing performed in the optical domain. Physical layer simulations show successful buffering and forwarding of 40-Gb/s optical packets with 2-dB power penalty     

High-speed, all-optical XOR gates using semiconductor optical amplifiers in ultrafast nonlinear interferometers

We will review three recently-proposed high-speed, all-optical Exclusive OR (XOR) gates operating at 40 and 85?Gb/s, which were demonstrated using ultrafast nonlinear interferometers (UNIs) incorporating semiconductor optical amplifiers (SOAs). The first 40-Gb/s XOR gate was obtained using a dual UNI configuration. The second is a 40-Gb/s XOR gate without additional probe beam required, where the only inputs launched into the setup were data A and B. The XOR logic of data A and B is the sum of two components (A)B and(A)B , each of which was obtained from the output of UNI via cross-phase modulation (XPM) in SOAs. Furthermore, an 85-Gb/s XOR gate is, by far, the fastest XOR gate realized by SOAs, which was also demonstrated using a dual UNI structure. The operating speed of the XOR gate was enhanced by incorporating the recently proposed turbo-switch configuration. In addition, the SOA switching pulse energies of these XOR gates were lower than 100 fJ.     

Study of the operating regime for all-optical passive 2Rregeneration of dispersion-managed RZ data at 40 Gb/s using in-lineNOLMs

In this letter, we numerically demonstrate that the use of inline nonlinear optical loop mirrors in strongly dispersion-managed transmission systems dominated by pulse distortion and amplitude noise can achieve all-optical passive 2R regeneration of a 40-Gb/s return-to-zero data stream. We define the tolerance limits of this result to the parameters of the input pulses     

An Optically Clocked Transistor Array for High-Speed Asynchronous Label Swapping: 40 Gb/s and Beyond

We describe the development of an optically clocked transistor array (OCTA) interface device for label swapping high-speed asynchronous burst optical packets. The OCTA integrates the three critical functions of serial-to-parallel (SP) conversion, parallel-to-serial (PS) conversion, and clock-pulse generation into a simple optoelectronic integrated circuit (OEIC) to create a single-chip interface between the input/output baseband optical labels and a CMOS label processor. The result is a high-performance label swapping solution which is compact and low power. In this paper, a detailed investigation of the design and optimization of the circuit is first performed, followed by testing of device stability under subsystem operating conditions. Finally, demonstrations of single-channel switching speeds allowing greater than 100-Gb/s operation, 40-Gb/s SP and PS conversion with an eight-channel OCTA, and error-free label swapping of 10-Gb/s asynchronous optical packets with a prototype label swapper module are described.     

Ultrafast all-optical pattern matching using differential spin excitation and its application to bypass/drop self-routing for asynchronous optical packets

This paper presents a novel scheme for ultrafast all-optical pattern matching using the differential spin excitation in semiconductor multiple quantum wells (MQWs). In a demonstration of an all-optical pattern matching between two 100-Gb/s 16-bit optical packets, the contrast ratio of the photodiode (PD) output from the pattern matcher, between the pattern matched and the pattern-unmatched cases, was more than four for packets with a 2-dB power fluctuation. As an application of the pattern matcher to optical-packet-switched ring networks, bypass/drop self-routing is demonstrated for asynchronous 100-Gb/s 32-bit optical packets with 8-bit labels. In the experiment, a label of an incoming packet was compared to a local address (LA) given to a node in the optical domain. By changing the pattern of the LA packet instead of that of the incoming packet, the pattern matching was carried out for packets with various kinds of patterns. The contrast ratio of the PD output was more than six for all patterns.     

320-to-40-gb/s demultiplexing using a single SOA assisted by an optical filter

We demonstrate excellent all-optical demultiplexing of 40-Gb/s base-rate channels out of 160- and 320-Gb/s single polarization optical time-division-multiplexed data streams. The demultiplexer utilizes a semiconductor optical amplifier and an optical filter placed at the amplifier output. The center wavelength of the filter is blue-shifted from the wavelength of the clock signal, so that ultrafast chirp dynamics can be employed for optical switching. Error-free demultiplexing was achieved at very low optical switch powers: 3.5 mW (160-Gb/s data), 6.3 mW (320-Gb/s data), and 0.09 mW (40-GHz clock). The proposed demultiplexer has a simple structure and allows monolithic integration.     

All-Optical Processing Based on a Logic xor Gate and a Flip-Flop Memory for Packet-Switched Networks

The routing functionality by all-optically interconnecting semiconductor-based all-optical logic gates and flip-flops is demonstrated in the frame of an all-optical label swapping (AOLS) network. We experimentally show that the output of the all-optical 2-bit correlator is capable of toggling the states of the integrated flip-flop every 2.5 ns via an adaptation stage. High extinction ratios are obtained at the output of the flip-flop, which can be used to feed a high-speed wavelength converter to complete the routing functionality of the AOLS node. The potential integration of these semiconductor optical amplifier integrated Mach-Zehnder interferometer-based devices make the proposed approach a very interesting solution for future packet switched optical networks.     

All-Optical Chromatic Dispersion Monitoring for Phase-Modulated Signals Utilizing Cross-Phase Modulation in a Highly Nonlinear Fiber

We propose and experimentally demonstrate an all-optical chromatic dispersion (CD) monitoring technique for phase-modulated signals utilizing the cross-phase-modulation effect between the input signal and the inserted continuous-wave probe. The probe's optical spectrum changes with the accumulated CD on the input signal, indicating that the optical power variations can be measured for monitoring. The experimental results show that this technique can monitor up to 120 ps/nm of CD for a 40-Gb/s return-to-zero differential phase-shift keying (RZ-DPSK) transmission system, with the maximum measured optical power increment of 16.5 dB. The applicability of this monitoring technique to higher bit-rate phase-modulated signals, such as 80-Gb/s RZ differential quadrature phase-shift keying and 80-Gb/s polarization-multiplexed RZ-DPSK, is also investigated via simulation.      

Optical subcarrier labeling transparent to the payload format using carrier suppression technique

In this letter, we propose an optical subcarrier labeling technique that guarantees the transparency to the payload modulation format based on carrier suppression of the payload. We experimentally demonstrate transparent wavelength conversion based on four-wave mixing in a highly nonlinear fiber and subcarrier label insertion for a 10-Gb/s differential phase-shift keying payload and a 155-Mb/s amplitude shift keying subcarrier label with an overall penalty of 1.8 dB for the payload and 1.7 dB for the label.     

All-Optical Packet-Switching Decoder Design and Demonstration at 10 Gb/s

A 3 times 8 all-optical decoder based on cross-polarization modulation in semiconductor optical amplifiers is demonstrated for the first time to our knowledge. The design requires a single active optical device per output. Experimental results are shown for return-to-zero modulated 10-Gb/s signals. Applications include label processing in optical packet switched optical networks     

Ultrafast Time-Spread Optical BPSK Code Label Generation and Processing Based on Variable-Bandwidth Spectrum Shaper

In experiments, we demonstrated time-spread 200-Gchip/s 10-Gb/s eight-chip optical binary phase-shift keying code generation and matched filtering based on spectral amplitude and phase control. By using a bandwidth-tunable high-resolution optical spectrum controller that we have previously developed, we were able to control spectral components with 10-GHz resolution in the entire $C$-band, with rectangular passbands. To demonstrate the application of this spectrum controller to tunable optical label processing, we performed experiments and simulated label generation and processing by controlling the spectrum.      

All-Optical 3R Burst-Mode Reception at 40 Gb/s Using Four Integrated MZI Switches

We demonstrate an all-optical retime, reshape, reamplify (3R) burst-mode receiver (BMR) operating error-free with a 40-Gb/s variable-length asynchronous optical data packets that exhibit up to 9-dB packet-to-packet power variation. The circuit is completely based upon hybrid integrated Mach-Zehnder interferometric (MZI) switches as it employs four cascaded MZIs, each one performing a different functionality. The 3R burst-mode reception is achieved with the combination of two discrete all-optical subsystems. A reshape, reamplify BMR employing a single MZI is used first to perform power equalization of the incoming bursts and provide error-free data reception. This novel approach is experimentally demonstrated to operate error-free, even for a 9-dB dynamic range of power variation between bursty data packets and for a wide range of average input power. The obtained power-equalized data packets are then fed into a 3R regenerator to improve the signal quality by reducing the phase and amplitude jitter of the incoming data. This packet-mode 3R regenerator employs three MZIs that perform wavelength conversion, clock extraction, and data regeneration for every packet separately and operates at 40 Gb/s, exhibiting rms timing jitter reduction from 4 ps at the input to 1 ps at the output and a power penalty improvement of 2.5 dB