Multi-wavelength Conversion Research Articles

Configurable all-optical multicast using cavity-enhanced four wave mixing in semiconductor ring laser

A novel all-optical multicast scheme based on cavity-enhanced four wave mixing in a monolithically integrated semiconductor ring laser (SRL) is proposed. By employing an injecting optical signal resonant with a cavity mode of the SRL, one-to-seven all-optical multicast by means of highly efficient simultaneous multi-wavelength conversion has been experimentally demonstrated up to multi-gigabit data rates. The scheme offers several advantages including low power penalty, reconfigurability, monolithic integration and low cost.

An Optical Wavelength-Routed Multicast Packet Switch Based on Multitimeslot Multiwavelength Conversion

This letter presents a new scheme to realize multicast operation in a wavelength-routed optical packet switch by adding multicast modules. The proposed multicasting scheme is based on multitimeslot multiwavelength conversion in conjunction with wavelength selection to resolve the problem of output contention.

Non-inverted multiple wavelength converter at 40 Gbit/s using 1550 nm quantum dot SOA

Error-free and low penalty (<2.5 dB) 1×4 multiwavelength conversion at 40 Gbit/s in a 1550 nm quantum dot semiconductor optical amplifier (QD-SOA) is demonstrated. The suggested converter makes use of a simplified filtering scheme based on a standard telecom grade dense wavelength division multiplexing demultiplexer (Demux). By detuning the wavelength of the continuous-wave probes out of the Demux's passband, a non-inverted wavelength converted signal is available at each of the Demux's outputs. Albeit significant fibre-to-fibre losses of the non-packaged QD-SOA (∼10 dB), only a low penalty is reported, mainly due to the low noise at the amplifier's output, with similar performance for a single and multiple wavelength conversion operation of the setup.

40-Gb/s All-Optical Serial-to-Parallel Conversion Based on a Single SOA

An all-optical serial-to-parallel converter (AOSPC) was experimentally demonstrated. It could potentially be used to process variable-length optical packets. This scheme mainly consists of wavelength interleaved pulse generation and the sequential multiwavelength conversion (SMWC). The SMWC is based on a single semiconductor optical amplifier. In this research, a 40-Gb/s serial optical signal was converted into four-channel 10-Gb/s parallel optical signals. This scheme has the advantages of a simple system configuration, integration potential, and polarization independency. In addition, the AOSPC is suitable for an input signal with a low optical signal-to-noise ratio and at the same time can regenerate degraded serial signals.

Ultrafast Raman Pulses in SOI Optical Waveguides for Nonlinear Signal Processing

Nonlinear optical signal processing by ultrafast Raman pulses in silicon-on-insulator rib waveguides is theoretically investigated in this paper. Stimulated Raman scattering, two-photon absorption, free carrier dispersion, self- and cross-phase-modulation-induced by Kerr effect, walk-off, group velocity dispersion, pump depletion, self-steeping, and polarization coupling are taken into account by a very general modeling under subpicosecond regime. Raman amplification, multiwavelength conversion, soliton formation, and pulse compression are presented and discussed. Finally, some simulations for generation of higher order Stokes pulses in mid-IR region are given.

Single to multi-wavelength conversion using gain modulation in an FP-LD

This work was supported by the Korean Science and egnineering Foundation (KOSEF) grant funded by the Korean Government (MEST).

40 Gbit/s wavelength multicast via SOA-MZI and applications

40 Gbit/s wavelength multicast is demonstrated by all-optical multi-wavelength conversion based on a single interferometer. Simultaneous 200 GHz spaced one-to-four conversion is achieved, error free until BER of 10−10 and with negligible sensitivity difference among all the multicast channels. Several new all-optical applications are also enabled by this technology.

Regenerative all-optical wavelength multicast for next generation WDM network and system applications

We experimentally demonstrate regenerative all-optical wavelength multicast by simultaneous multi-wavelength conversion of 10 Gb/s non-return-to-zero signals to four ITU 100 GHz spaced channels with a receiver sensitivity improvement of 1.84 dB and less than 0.14 dB difference among all the multicast channels, using a single commercial monolithically integrated SOA-MZI. The multicast device also exhibited about 22 dB optical signal-to-noise ratio enhancement for all the converted channels compared to the original signal channel without wavelength conversion. Our experiment for the first time revealed the regeneration properties of a SOA-MZI device for WDM wavelength multicast purposes, and proved the excellent performance of a simple scheme for various future network and system applications, such as all-optical wavelength routing and grid networking.

Performance Enhancement of Multiwavelength Conversion of RZ-DPSK Based on Four-Wave Mixing in Semiconductor Optical Amplifier

In this letter, we propose two methods to enhance the performance of multichannel wavelength conversion of return-to-zero differential phase-shift-keying signal in a semiconductor optical amplifier (SOA) based on four-wave-mixing effect. The first one is optimizing the relative time delay of the multichannel signal to reduce the crosstalk-induced penalty in SOA. The second one is using the synchronous clock pumping to raise the power of converted signal. The experiment on wavelength conversion of two channels at 10-Gb/s signal showed the power penalty was improved more than 1 dB in the first method and about 1.5 dB in the second method.

Multi-wavelength conversion at 10 Gb/s and 40 GHz based on nonlinear effects in HNLF

We present experimental results and numerical simulations of multiple-wavelength conversion of 10 Gb/s non-return-to-zero (NRZ) signals based on 2-pumps four-wave mixing and of 40Gb/s return-to-zero (RZ) signals through supercontinuum (SC) generation in a highly nonlinear fiber (HNLF). Two pumps with a 100 GHz separation located in the region of anomalous dispersion of the HNLF were combined to form a beat signal The 10 Gb/s NRZ signal anchored on ITU grid was converted with gain into 6 new signals and 6 idlers with 100 GHz separation. High quality sc with bandwidth exceeding 50 nm was generated when the HNLF was pumped with 25 dBm average power. Sliced sc can be used as a source for all-optical multicasting.

Multi-wavelength conversion at 10 Gb/s using cross-phase modulation in highly nonlinear fiber

In this paper we demonstrate a technique of signal wavelength conversion via cross-phase modulation (XPM)-induced nonlinear coupling among a 10GHz return-to-zero (RZ) signal and a continuous wave (CW) carrier co-propagating in dispersion-shifted (DS) highly nonlinear fiber (HNLF). The wavelength conversion bandwidth up to ±20nm was achieved experimentally and potential extension was verified by numerical simulations. The principle can easily be extended to 40Gb/s and used as polarization insensitive all-optical wavelength converter.

Theoretical and experimental performance evaluation of all‐optical multiwavelength conversion by four‐wave mixing in fiber at 10/20/40 Gb/s for optical layer multicast

AbstractAll‐optical multiwavelength conversion (MWC) enables optical layer multicast without electronic processing. Wavelength conversion by four‐wave‐mixing (FWM) offers strict transparency in bit rate and modulation format. In this letter, a novel FWM MWC scheme is proposed, supported by theoretical analysis and experimental performance evaluation at 10/20/40 Gb/s. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49:1067–1071, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22358

All-optical multi-wavelength conversion using absorption modulation of an injection-locked FP-LD

An all-optical multi-wavelength converter using absorption modulation of an injection-locked Fabry-Perot laser diode (FP-LD) is demonstrated at 2.5Gb/s. The multi-wavelength converter can simultaneously provide 1 to 4 channel outputs and support both inverted and non-inverted conversion. By optimizing the wavelength of pump signal and polarization states of pump, probes, and the FP-LD, all converted outputs show high extinction ratio and negligible crosstalk power penalty. The results guarantee to increase the number of output channels. The proposed scheme can be applied to multicasting functions as well as 1xN wavelength conversion in an all-optical wavelength division multiplexed network.

Demonstration of an optical-label switching router with multicast and contention resolution at mixed data rates

This letter experimentally demonstrates a scalable optical-label switching router architecture that supports a limited multicast function. A semiconductor-optical-amplifier-based Mach-Zehnder interferometer wavelength converter performs multiwavelength conversion for multicast at 10 Gb/s by cross-phase modulation. With a 2.5-Gb/s unicast channel, the experiment also demonstrates contention resolution in the wavelength domain at mixed data rates.

Double-stage cross-gain modulation in SOAs: an effective technique for WDM multicasting

We experimentally demonstrate an optical circuit capable of multiwavelength conversion. The circuit structure is intrinsically stable and polarization independent. It may thus be a practical solution for wavelength-division multiplexing multicasting applications. Its working principle relies on synchronous double-stage cross-gain modulation in SOAs between an incoming data-modulated signal and several local continuous wave lasers. We report the simultaneous wavelength conversion of an input 10Gb/s nonreturn-to-zero to eight 200-GHz-spaced output channels. The obtained signals show only a moderate optical signal-to-noise ratio penalty.

All-optical multi-wavelength conversion of 10 Gbit/s NRZ/RZ signals based on SOA-MZI for WDM multicasting

An all-optical multi-wavelength converter using a semiconductor optical amplifier based Mach-Zehnder interferometer is proposed and demonstrated. The proposed scheme can accommodate both NRZ and RZ format. WDM multicasting is confirmed by transmission experiment using conventional singlemode fibre before and after the multi-wavelength converter.

All-Optical Packet Compression Based on Time-to-Wavelength Conversion

We experimentally demonstrate a novel optical packet compression scheme based on linearly chirping the packets followed by dispersive compression and multiwavelength conversion back onto a single wavelength. In particular, four-bit packets at 10 Gb/s were compressed into four-bit packets at 40 Gb/s. Error-free performance was achieved for the final compressed packet.

Nonlinear multiwavelength conversion based on an aperiodic optical superlattice in lithium niobate

We have demonstrated what is to our knowledge the first successful achievement of multiwavelength conversion in an aperiodic optical superlattice (AOS) lithium niobate crystal with equalized gain. The two AOS devices in our experiment, numerically synthesized from 2857 crystal blocks with a unit block thickness of 3.5 microm, have fundamental wavelengths of 1540 and 1545 nm for double-wavelength second-harmonic generation (SHG) and of 1540, 1545, and 1553 nm for triple-wavelength SHG at 50 degrees C. Our experiment and simulation show that the output spectrum of an AOS wavelength converter is fairly insensitive to typical fabrication errors.