Experimental demonstration of fast simultaneous wavelength switching and time demultiplexing using a nonlinear optical loop mirror

Simultaneous all-optical high-speed wavelength switching and time demultiplexing is experimentally demonstrated using a nonlinear optical loop mirror, an integrated passive wavelength router, and fast optical space switches. With >1.2-GHz wavelength switching speeds and 2.5 Gb/s time demultiplexing speeds, both packet switching and isolated-bit extraction are demonstrated. The time switching can potentially be applied to data rates >100 Gb/s.     

All-optical regeneration and wavelength conversion in an integratedsemiconductor optical amplifier/distributed-feedback laser

Simultaneous all-optical regeneration and wavelength conversion is demonstrated at 2.488 Gb/s for the first time in an integrated distributed feedback laser/semiconductor optical amplifier. After 93 km of standard fiber, a negative sensitivity penalty of -1.3 dB is achieved upon wavelength converting all-optically from 1538 to 1553.5 nm     

Optical signal processing for optical packet switching networks

Optical packet switching promises to bring the flexibility and efficiency of the Internet to transparent optical networking with bit rates extending beyond that currently available with electronic router technologies. New optical signal processing techniques have been demonstrated that enable routing at bit rates from 10 Gb/s to beyond 40 Gb/s. We review these signal processing techniques and how all-optical-wavelength converter technology can be used to implement packet switching functions. Specific approaches that utilize-ultra-fast all-optical nonlinear fiber wavelength converters and monolithically integrated optical wavelength converters are discussed and research results presented.     

All-optical wavelength conversion using a pulse reformatting optical filter

We introduce a general concept for the design of all-optical wavelength converters with pulse reformatting functionality. The novel wavelength converters are based on a single semiconductor optical amplifier followed by an optical filter. A microelectromechanical system-based realization is shown and simultaneous 40 Gb/s wavelength conversion, switching and signal format conversion is demonstrated. The new pulse reformatting optical filter device outperforms current schemes with respect to input-power requirements, input-power dynamic range and signal quality.     

160 Gb/s variable length packet/10 Gb/s-label all-optical label switching with wavelength conversion and unicast/multicast operation

We report on the first demonstration of all-optical label switching (AOLS) with 160 Gb/s variable length packets and 10 Gb/s optical labels. This result demonstrates the transparency of AOLS techniques from previously demonstrated 2.5 Gb/s to this 160 Gb/s demonstration using a common routing and packet lookup framework. Packet forwarding/conversion, optical label erasure/re-write and signal regeneration at 160 Gb/s is achieved using a WDM Raman enhanced all-optical fiber cross-phase modulation wavelength converter. It is also experimentally shown that this technique enables packet unicast and multicast operation at 160 Gb/s. The packet bit-error-rate is measured for all optical label switched 16 /spl times/ 10 Gb/s channels and error free operation is demonstrated after both label swapping and packet forwarding.     

Demonstration of an all-optical simultaneous wavelengthconverting/space-switching cross-point device

An integrated device consisting of two cascaded 2×2 crosspoint switches has been utilized to demonstrate a highly functional integrated routing and wavelength converting switch architecture at a data rate of 2.488 Gb/s. This aliens simultaneous space switching and wavelength conversion of optical signals in wavelength-division multiplexed (WDM) networks. Eye diagrams and bit-error-rate (BER) curves are displayed for wavelength conversion and simultaneous routing of a separate signal     

Wide-range all-optical wavelength conversion usingdual-wavelength-pumped fiber Raman converter

A wavelength conversion scheme based on a fiber Raman converter is proposed, in which an externally injected high power pump laser and the associated Stokes laser are used to assist the Raman conversion process of signal light coded with optical information. Because the Raman gain spectrum in fibers is extremely broad, a wavelength conversion device with wide-range tunability is feasible. We numerically demonstrate that wavelength conversion from 1.31 to 1.42 μm can be realized using a fiber Raman converter at up to 10 Gb/s with an efficiency of 18%. It is also demonstrated that wide range conversion from 1.31 to 1.55 μm for optical fiber communication is feasible at up to 5 Gb/s when the fiber Raman converters are cascaded twice     

All-optical wavelength conversion by semiconductor opticalamplifiers

Following a brief introduction to the applications for wavelength conversion and the different available conversion techniques, the paper gives an in depth analysis of cross gain and cross phase wavelength conversion in semiconductor optical amplifiers. The influence of saturation filtering on the bandwidth of the converters is explained and conditions for conversion at 20 Gb/s or more are identified. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths. This can be overcome using cross phase modulation in semiconductor optical amplifiers that are integrated into interferometric structures. The first results for monolithic integrated interferometric wavelength converters are reviewed, and the quality of the converted signals is demonstrated by transmission of 10 Gb/s converted signals over 60 km of nondispersion shifted single mode fiber     

A 10-Gb/s Monolithically Integrated Filterless InGaAsP/InP Widely Tunable Wavelength Converter With Conversion Gain

In this paper, we present the details of a monolithically integrated filterless wavelength converter based on photocurrent-driven technology. The device consists of an integrated tunable laser transmitter and an optical receiver. The transmitter includes a sampled-grating distributed-Bragg-reflector laser, an electroabsorption modulator, and a semiconductor optical amplifier. The optical receiver employs two semiconductor optical amplifiers and a quantum-well p-i-n photodetector. The wavelength converter is characterized at 10 Gb/s over a variety of bias conditions at various input-power levels in various digital-system experiments. Bit-error-rate measurements at 10 Gb/s over an output tuning range of 32 nm between 1531 and 1563 nm show power penalties less than 1 dB. Similar experiments over an input wavelength range of 25 nm from 1535 to 1560 nm show a power penalty less than 2.5 dB. For a wavelength conversion from 1548 nm to a range of output wavelengths between 1531 and 1563 nm, the facet-to-facet gain ranges from 9 to 13 dB, neglecting fiber coupling losses.     

All-optical pulse width and wavelength conversion at 10 Gb/s usinga nonlinear optical loop mirror

An all-optical pulse width and wavelength converter is demonstrated using a nonlinear optical loop mirror. The conversion of a 10 Gb/s, 8 ps pulse width data stream at 1551 nm to a 23 ps pulse width data stream at 1543 nm is demonstrated. The control pulse energy required for switching is 10 pJ. Bit-error-rate measurements are presented     

Bistability and waveform reshaping in a DFB-LD with side-mode lightinjection

Bistability is observed in wavelength conversion using a DFB-LD with side-mode light injection. Under appropriate wavelength detuning conditions, switching and hysteresis appear between the “on” and “off” states of the original laser oscillation. Utilizing this characteristic, waveform reshaping is demonstrated at a modulation speed of 3 Gb/s     

Tunable Wavelength Conversion Using Cross-Gain Modulation in a Vertically Coupled Microring Laser

Wavelength conversion using self-pumped cross-gain modulation in a microring laser vertically coupled to a passive waveguide is presented. Successful conversion at 2.5 Gb/s along with a 100-km transmission is demonstrated. Tunable conversion from almost any wavelength of the gain bandwidth to any of the three supported modes of the laser is shown and the limitations of the method, related to mode switching of the laser, are also briefly discussed.     

Finely tunable wavelength conversion of high bit-rate signals byusing a superstructure-grating distributed Bragg reflector laser

Finely tunable wavelength conversion of high bit-rate signals is analyzed numerically and demonstrated experimentally-to a wavelength range from 1530 to 1560 nm-by using a superstructure-grating distributed Bragg reflector laser. Transmission of a 10 Gb/s converted signals over a 100 km-long optical fiber is also demonstrated using a dispersion-shifted optical fiber     

Polarization-insensitive wavelength conversion up to 10 Gb/s basedon four-wave mixing in a semiconductor optical amplifier

Polarization-insensitive wavelength conversion at 2.5 and 10 Gb/s using four-wave mixing in a bulk semiconductor optical amplifier is reported. At 10 Gb/s, a conversion range from 6.4-nm wavelength downshift to 4.8-nm upshift has been demonstrated. The conversion efficiency and signal-to-noise ratio versus conversion range are also characterized     

40-Gb/s all-optical wavelength conversion based on a nonlinearoptical loop mirror

All-optical wavelength conversion based on a nonlinear optical loop mirror (NOLM) at 40 Gb/s is demonstrated for the first time. The effect of walkoff time between control beam and signal beams is investigated when the NOLM is used as an all-optical wavelength converter or an all-optical demultiplexer     

High-Speed Wavelength Converter Capable of Converting the Same Wavelength Using a Single SOA in a Counterpropagation Scheme

We present a high-speed optical wavelength converter that is capable of converting the data to the same wavelength using a single semiconductor optical amplifier. Error-free wavelength conversion is demonstrated at a bit-rate of 40 Gb/s. The wavelength converter utilizes a counterpropagation scheme assisted by blue-detuned optical filtering technology. The blue-detuned optical filter shortens the recovery time of the wavelength converter, from initial 100 ps down to less than 6 ps, ensuring 40-Gb/s operation. The counterpropagation scheme shows a slow gain saturation time, which becomes a determinant factor for the operating speed of the proposed system. This wavelength converter is constructed by using commercially available fiber pigtailed components. It has a simple configuration and allows photonic integration.      

40-Gb/s Polarization-Insensitive All-Optical Clock Recovery Using a Quantum-Dot Fabry–PÉrot Laser Assisted by an SOA and Bandpass Filtering

We experimentally demonstrate polarization- insensitive all-optical clock recovery using a passively mode-locked quantum-dot Fabry–PÉrot (QD-FP) semiconductor laser at 40 Gb/s. Polarization insensitivity is achieved by using a wavelength conversion stage based on cross-phase modulation in a semiconductor optical amplifier and optical bandpass filtering. A clock signal with a root-mean-square timing jitter of 300 fs is recovered for an input data signal with a scrambled state-of- polarization (SOP). This is comparable to that from the QD-FP laser alone for an input signal with a fixed SOP. Moreover, an improvement in the tolerance to a degradation in the optical signal-to-noise ratio of the input signal is achieved by the use of the wavelength conversion stage.      

Widely Tunable Separate Absorption and Modulation Wavelength Converter With Integrated Microwave Termination

A widely tunable wavelength converter utilizing a separate absorption and modulation configuration and only dc bias connections is demonstrated. The device integrates an SG-DBR laser with a traveling-wave electroabsorption modulator and an optically pre-amplified receiver and introduces a simplified bias scheme by the inclusion of passive resistor and capacitor circuit elements. We discuss a the design of these passive elements and their compatibility with fabrication of photonic integrated circuits. The device demonstrates over 12 GHz optical bandwidth and error free 10 Gb/s wavelength conversion is achieved with less than 2.5 dB power penalty over 25 nm of output tuning.     

Multifunctional photonic switching operation of 1500 nm Y-coupledcavity laser (YCCL) with 28 nm tuning capability

The authors present new results on extended electrical tuning, fast spatial switching, and optically controlled wavelength conversion characteristics for the recently developed InP-based Y-laser structure. The devices have a 80 nm thick bulk InGaAsP active layer and are completely grown by metalorganic vapor phase epitaxy. The facets at both ends of the chip are as-cleaved without antireflective coating. The addressable range for electrically controlled wavelength switching was extended to the record value of 28 nm. When operated as a lossless 1:2 optical space switch, fiber-to-fiber gain >0 dB, extinction ratio >50 dB and high speed operation up to 1 Gb/s were shown. Optically triggered tunable wavelength conversion including dynamic operation was also demonstrated     

168-Gb/s all-optical wavelength conversion with asymmetric-Mach-Zehnder-type switch

Error-free all-optical wavelength conversion at 168 Gb/s, which is the highest repetition rate ever reported, has been achieved by using a symmetric-Mach-Zehnder (SMZ)-type switch. Low-power-penalty 84-Gb/s operation is also demonstrated. The push-pull switching mechanism of the SMZ switch enables such ultrafast operation based on cross-phase modulation associated with the carrier depletion in a semiconductor optical amplifier. The configuration of the delayed-interference signal-wavelength converter, which is a simplified variant of the SMZ switch, is used in this experiment