Wavelength Multicasting Research Articles

One-to-Sixteen Wavelength Multicast of Optical Single-Sideband OFDM Signals Using a Single Pulsed Pump

We demonstrate an effective wavelength multicast scheme to generate 16 new channels with low penalty and high spectral efficiency using a single optical pump. The scheme capitalizes on cross-phase modulation of an input signal by a rate-multiplied pump pulse train to generate multiple wavelength channels. The pulse rate is multiplied in an energy-efficient way via the temporal Talbot effect. In the experiment, we have successfully achieved more than 20 multicast copies of a 40-Gb/s QPSK OFDM single-sideband signal. The copied channels are spaced by 50 GHz which is determined by five times multiplication on the repetition rate of a 10-GHz input pump pulse train. The BER performances of the central 16 channels are evaluated, showing less than 1.3-dB OSNR difference among the channels. Compared to the original single-sideband signal, the central channel experiences only a 0.1-dB OSNR penalty in our approach. The result verifies the effectiveness of our scheme in realizing spectrally efficient and high-channel-count wavelength multicast by using a single pump generated with relatively low-speed electronic resources.

On-chip high-efficiency wavelength multicasting of PAM3/PAM4 signals using low-loss AlGaAs-on-insulator nanowaveguides.

Nonlinear optics-based optical signal processing (OSP) could potentially increase network flexibility because of its transparency, tunability, and large bandwidth. A low-loss, high nonlinearity, and compact integrated material platform is always the pursuit of OSP. In this Letter, a high-efficiency, one-to-six wavelength multicasting of 10 Gbaud pulse-amplitude modulation (PAM3/PAM4) signals using a 6 cm long Al0.2Ga0.8As-on-insulator nanowaveguide is experimentally demonstrated for the first time, to the best of our knowledge. The low-loss, combined with the high nonlinear coefficient of the AlGaAsOI platform, enables us to achieve -11.2dB average conversion efficiency clear eye diagrams and <2.1dB power penalty at KP4-forward error correction threshold (2.4×10-4) for all the output PAM3/PAM4 multicasting channels. This result points to a new generation of nonlinear OSP photonic integrated circuits.

All-Optical OOK -to-QPSK Modulation Format Conversion With Wavelength Multicasting Based on Cascaded SOA Configuration

An on–off keying (OOK) to quadrature phase shift keying (QPSK) format conversion scheme has been demonstrated in this paper. Two-channel OOK signals are converted into one-channel QPSK signal, and accompanied with a multicast function. The proposed scheme is based on a cascaded semiconductor optical amplifiers (SOA) configuration where the processes of cross phase modulation (XPM) and nonlinear polarization rotation (NPR) are properly controlled by OOK signals in each SOA. The experimental results show that after conversion, four-channel QPSK signals are successfully obtained with open eye-diagrams, and all the converted signals experience a small power penalty of less than 3.4 dB at a bit error rate (BER) of $10^{-9}$ compared to the original signal. In addition, the optical spectra and the constellation diagrams of the converted signal also indicate the high quality performance exhibited by the proposed format conversion scheme.

Experimentally validated full-vectorial model of wavelength multicasting via four-wave mixing in straight waveguides

We derive full-vectorial nonlinear propagation equations of dual-pumped four-wave mixing in straight waveguides, which are valid in characterizing the one-to-six wavelength multicasting. Special attention is paid to the resulting idler wavelengths and their conversion efficiency, which enables the optimization of the experimental designs, including the incident wavelength and the power of pumps and signal. We validate the model by comparing the numerical simulation to the experimental measurement in a silicon-on-insulator waveguide, for the first time to our best knowledge, and achieve a good agreement. We further derive the general form of the proposed model for the case of using multiple,pumps, which holds a potential to numerically predict the performance of complex wavelength multicasting, and essentially guide the waveguide designs.

Investigation on Expanding the Computing Capacity of Optical Programmable Logic Array Based on Canonical Logic Units

A general structure of an all-optical canonical logic based programmable logic array (CLUs-PLA) based on three methods to expand its computing capacity is presented. These methods include introducing bidirectional structure for nonlinear devices, utilizing wavelength multicast of four-wave mixing (FWM), and exploiting different nonlinear effects simultaneously, which fully utilize the parallelism of optical signals. Aiming at this general structure, we quantitatively analyze its computing capacity in detail, which is obviously enlarged comparing with the standard CLUs-PLA. To demonstrate our proposal, an experiment of CLUs’ simultaneous generation in nine parallel wavelength channels using bidirectional FWM is carried out. Comparing with the standard CLUs-PLA, the computing capacity of the expanded one is enlarged to 7.5 times.

Enhanced Performance of Wavelength Multicasting by Gain-Transparent Stimulated Brillouin Scattering

Enhanced Performance of Wavelength Multicasting by Gain-Transparent Stimulated Brillouin Scattering

Integrated all-optical wavelength multicasting for 40 Gbit/s PDM-QPSK signals using a single silicon waveguide

All-optical wavelength multicasting is presented and experimentally demonstrated for 40Gbit/s polarization-division-multiplexed (PDM) nonreturn-to-zero quadrature phase-shift keying (QPSK) signals using four-wave mixing (FWM) with angled-polarization pumps in a silicon waveguide. Five multicast channels are obtained on the generated idlers. The eye diagrams, constellation diagrams, and bit error rates (BERs) of the QPSK sequences on the two polarization states are measured for each wavelength channel. The power penalties of all these multicast QPSK sequences on x or y polarization state are less than 2.0dB at the BER of 3×10−3.

Wavelength multicasting through four-wave mixing with an optical comb source.

Based on four-wave mixing (FWM) with an optical comb source (OCS), we experimentally demonstrate 26-way or 15-way wavelength multicasting of 10-Gb/s differential phase-shift keying (DPSK) data in a highly-nonlinear fiber (HNLF) or a silicon waveguide, respectively. The OCS provides multiple spectrally equidistant pump waves leading to a multitude of FWM products after mixing with the signal. We achieve error-free operation with power penalties less than 5.7 dB for the HNLF and 4.2 dB for the silicon waveguide, respectively.

Flexible and scalable wavelength multicast of coherent optical OFDM with tolerance against pump phase-noise using reconfigurable coherent multi-carrier pumping.

Recently the ever-growing demand for dynamic and high-capacity services in optical networks has resulted in new challenges that require improved network agility and flexibility in order for network resources to become more "consumable" and dynamic, or elastic, in response to requests from higher network layers. Flexible and scalable wavelength conversion or multicast is one of the most important technologies needed for developing agility in the physical layer. This paper will investigate how, using a reconfigurable coherent multi-carrier as a pump, the multicast scalability and the flexibility in wavelength allocation of the converted signals can be effectively improved. Moreover, the coherence in the multiple carriers prevents the phase noise transformation from the local pump to the converted signals, which is imperative for the phase-noise-sensitive multi-level single- or multi-carrier modulated signal. To verify the feasibility of the proposed scheme, we experimentally demonstrate the wavelength multicast of coherent optical orthogonal frequency division multiplexing (CO-OFDM) signals using a reconfigurable coherent multi-carrier pump, showing flexibility in wavelength allocation, scalability in multicast, and tolerance against pump phase noise. Less than 0.5 dB and 1.8 dB power penalties at a bit-error rate (BER) of 10-3 are obtained for the converted CO-OFDM-quadrature phase-shift keying (QPSK) and CO-OFDM-16-ary quadrature amplitude modulation (16QAM) signals, respectively, even when using a distributed feedback laser (DFB) as a pump source. In contrast, with a free-running pumping scheme, the phase noise from DFB pumps severely deteriorates the CO-OFDM signals, resulting in a visible error-floor at a BER of 10-2 in the converted CO-OFDM-16QAM signals.

Integrated nonlinear interferometer with wavelength multicasting functionality.

Nonlinear interference based on four wave mixing (FWM) is extremely attractive due to its phase sensitivity. On the other hand, wavelength multicasting, which supports data point-to-multipoint connections, is a key functionality to increase the network efficiency and simplify the transmitter and receiver in the wavelength-division multiplexing systems. We propose and experimentally demonstrate a nonlinear interferometer with wavelength multicasting functionality based on single-stage FWM in an integrated silicon waveguide. With a three-pump and dual-signal input, four phase sensitive idlers are obtained at the interferometer output. For a proof-of-concept application, we further theoretically demonstrate the multicasting logic exclusive-OR (XOR) gate for both intensity and phase modulated signals. The proposed scheme would be potentially applied in various on-chip applications for future optical communication system.

Comparison of One- and Three-Mode Phase-Sensitive Wavelength Multicasting

Dual-pump driven, dispersion-synthesized parametric mixers have been identified as an efficient means for wavelength multicasting. In particular, four-mode phase-sensitive (PS) architecture, seeded by frequency-locked and phase-correlated four input optical signals, allows the parametric multicasting operated with ultralow noise and regenerative properties. To further corroborate the superiorities of the multimode PS operation, degenerate one- and three-mode PS parametric multicasting were numerically and experimentally compared, in terms of stability, phase manipulation, gain, and conversion efficiency, as well as noise performance.

All-optical NRZ-to-RZ format conversion at 10 Gbit/s with 1-to-4 wavelength multicasting exploiting cross-phase modulation & four-wave-mixing in single dispersion-flattened highly nonlinear photonic crystal fiber

All-optical NRZ-to-RZ format conversion with a function of wavelength multicasting is proposed in this paper, which is realized by exploiting cross-phase modulation (XPM) and four-wave-mixing (FWM) in a dispersion-flattened highly nonlinear photonic crystal fiber (DF-HNL-PCF). The designed format converter is experimentally demonstrated, for which the 1-to-4 wavelength multicasting is achieved simultaneously by filtering out two FWM idler waves and both blue-chirped and red-chirped components of the broadened NRZ spectrum induced by XPM. Moreover, the wavelength tunability and dynamic characteristics of the proposed NRZ-to-RZ format converter are also exploited using the different central wavelengths of an optical clock signal and varying the input optical power at a DF-HNL-PCF in our experiment. It is shown that the designed format converter can possess a wide range of operational wavelength over 17 nm, an optimal extinction ratio of 11.6 dB, and a Q-factor of 7.1, respectively. Since the proposed scheme uses an optical fiber-based configuration and is easy for implementation, it can be very useful for future applications in advanced fiber-optic communication networks.

Design of optical time-division multiplexed systems using the cascaded four-wave mixing in a highly nonlinear photonic crystal fiber for simultaneous time demultiplexing and wavelength multicasting

This paper reports a new design of optical time-division multiplexed (OTDM) systems that possess a functionality of simultaneous time demultiplexing and wavelength multicasting based on the cascaded four-wave mixing in a dispersion-flattened highly nonlinear photonic crystal fiber (DF-HNL-PCF). A module of OTDM demultiplexing and wavelength multicasting can be feasibly implemented by using a 3 dB optical coupler, a high-power erbium-doped fiber amplifier, a short-length DF-HNL-PCF, and a wavelength demultiplexer in the simple configuration. We also carry out an experiment on the proposed system to demonstrate the 100–10 Gbit s−1 OTDM demultiplexing with wavelength conversion simultaneously at 4 multicast wavelengths. It is shown that error-free wavelength multicasting is achieved on two wavelength channels with the minimum power penalty of 3.2 dB relative to the 10 Gbit s−1 back-to-back measurement, whereas the bit error rates of other two multicasting channels are measured to be about 10−6–10−5. Moreover, we propose the use of a proper error-correcting code to improve the multicasting performance of such an OTDM system, and our work reveals that the resulting system can theoretically support error-free multicasting of the OTDM-demultiplexed signal on four wavelength channels.

Wavelength Multicasting at 22-GBaud 16-QAM in a Silicon Nanowire Using Four-Wave Mixing

We demonstrate 1-to-6 wavelength multicasting of a 22-GBaud 16-QAM single polarization ( $6\times 88$ Gb/s) signal based on four-wave mixing in a dispersion engineered silicon nanowire. All six multicast signals perform below the bit error rate forward error correction threshold of $3.8\times 10^{-3}$ , with a worst case power penalty of 8 dB. We compare our wavelength multicasting performance against the theoretical power transfer during a three-wave mixing process and show that the average power of degenerate idlers agrees with the predicted 6 dB difference with respect to that of nondegenerate idlers. When distinguishing the nonlinear conversion efficiency from the absolute idlers power at the output of the silicon nanowire, we also show the importance of the output grating coupler’s loss and how it impacts the multicasting performance, in conjunction with the four-wave mixing efficiency.

Suppression of Inter-channel Higher Order Four Wave Mixing in Four-Mode Phase-Sensitive Parametric Wavelength Multicasting

Phase manipulation of four-mode phase-sensitive (4MPS) process was developed as a means for suppression of high-order four wave mixing (HoFWM) terms in dual-pump driven parametric wavelength multicasting and, consequently, for reduction of inter-channel crosstalk and inter-channel interference. In contrast to the previous studies that focused on power stabilization and conversion efficiency maximization, the investigation in this paper focuses on the evolution of the inter-channel HoFWM tones, whose suppression can be accomplished by arranging the phases of signals in a complementary manner. In addition, broadband 4MPS multicasting with suppressed HoFWM effects over 100-nm bandwidth, reaching up to 12-dB suppression ratio was demonstrated.

One to Six Wavelength Multicasting of RZ-OOK Based on Picosecond-Width-Tunable Pulse Source with Distributed Raman Amplification

One to Six Wavelength Multicasting of RZ-OOK Based on Picosecond-Width-Tunable Pulse Source with Distributed Raman Amplification

Simultaneous multichannel wavelength multicasting and XOR logic gate multicasting for three DPSK signals based on four-wave mixing in quantum-dot semiconductor optical amplifier.

In this paper, we experimentally demonstrate simultaneous multichannel wavelength multicasting (MWM) and exclusive-OR logic gate multicasting (XOR-LGM) for three 10Gbps non-return-to-zero differential phase-shift-keying (NRZ-DPSK) signals in quantum-dot semiconductor optical amplifier (QD-SOA) by exploiting the four-wave mixing (FWM) process. No additional pump is needed in the scheme. Through the interaction of the input three 10Gbps DPSK signal lights in QD-SOA, each channel is successfully multicasted to three wavelengths (1-to-3 for each), totally 3-to-9 MWM, and at the same time, three-output XOR-LGM is obtained at three different wavelengths. All the new generated channels are with a power penalty less than 1.2dB at a BER of 10(-9). Degenerate and non-degenerate FWM components are fully used in the experiment for data and logic multicasting.

All-optical non-conjugated wavelength multicasting of QPSK signal with capability of phase regeneration.

We propose all-optical one-to-three non-conjugated wavelength multicasting of QPSK signal with capability of phase regeneration, using dual-conjugated-pump phase sensitive amplification (PSA). Based on the seven-wave model, we can obtain phase transfer functions of individual multicasting channel. Different from two multicasting copies, the phase regeneration performance of input signal is determined by the nonlinear phase shift. Moreover, the optimal squeezing points of three multicasting channels have a deviation. Thus, there exists a regeneration performance trade-off among three multicasting channels. Our numerical simulation shows that the error vector magnitude (EVM) of 50 Gb/s QPSK signal can be successfully improved when both nonlinear phase shift and four-state position in its constellation are optimized. The calculated BER curves verify that the OSNR penalties of three multicasting channels are improved by around 1dB at BER = 10(-3).

Optical Network Node Supporting One-to-Six WDM Multicasting of QPSK Signals

The capability of multicast directly in the optical domain at the routing nodes is a target for energy saving, fast service provisioning, and effective network resource utilization. An optical network node architecture supporting wavelength conversion, unicast, and multicast is presented and a shared multicast/wavelength conversion module is designed in the intermediate node. Wavelength conversion and one-to-six WDM multicast of 25-Gb/s QPSK signals based on four-wave mixing are experimentally demonstrated using a semiconductor optical amplifier with only two pumps. All six multicast signals achieve error-free performance with a power penalty <;4.3 dB.

Demonstration of 100 Gbit/s optical time‐division demultiplexing with 1‐to‐4 wavelength multicasting using the cascaded four‐wave mixing in photonic crystal fiber with a single control light source

ABSTRACTDispersion‐flattened highly nonlinear (DF‐HNL) photonic crystal fibers are useful for ultrafast optical signal processing. In this article, 100 Gbit/s‐to‐10 Gbit/s optical time demultiplexing with simultaneous 1‐to‐4 wavelength multicasting is successfully demonstrated by use of the cascaded four‐wave mixing (FWM) in a 50 m DF‐HNL photonic crystal fiber, for the first time. This scheme uses a single control‐pulse light source only and a simple architecture. The wavelength multicasting of the time‐demultiplexed optical signal is achieved on four wavelength channels of which two can have the minimum power penalty of 3.2 dB at 10−9 bit error rate compared to the 10 Gbit/s back‐to‐back measurement. With the cascaded FWM, our proposed scheme can be used to improve the functionality of ultrahigh‐speed optical time‐division multiplexed systems/networks so as to support wavelength multicasting applications in a cost‐effective manner. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2330–2335, 2014