Repeated wavelength conversion of 10 Gbit/s signal usingwavelength-tunable semiconductor lasers

Repeated wavelength conversion of 10 Gbit/s pseudorandom non-return-to-zero signals is demonstrated using superstructure grating distributed Bragg reflector lasers operating in the 1.55-μm wavelength region. Error-free and very low-power-penalty wavelength conversion can be achieved in both first and second wavelength conversion for a fixed converted wavelength over a broad wavelength range from 1.486 to 1.573 μm (about 90-nm wide). The power penalty of the transmitted signal light through the first wavelength conversion device increases when the converted wavelength is switched from 1.544 to 1.573 μm periodically at a repetition frequency of 40 MHz. The increase in power penalty, however, is less than 6 dB even when the bit error rate is 10^-12     

4 Gb/s optical wavelength conversion using semiconductor opticalamplifiers

Semiconductor optical amplifiers used for efficient wavelength conversion up to 4 Gb/s are discussed. The rise and fall times as well as extinction ratio are experimentally analyzed. System performance at 4 Gb/s is evaluated showing a penalty of only 1.5 dB for the converted signal for conversion over 17 nm     

Wavelength conversion at 10 Gb/s using a semiconductor opticalamplifier

Data at 10 Gb/s has been translated from an input signal wavelength to another wavelength, either longer or shorter, using gain compression in a 1.5-μm semiconductor optical amplifier for wavelength conversion. To achieve operation at such high bit rates, the probe (shifted) input must be intense enough to compress the gain of the amplifier significantly. This reduces the gain recovery time of the amplifier because of probe stimulated emission. A consequence of the intense probe is an extinction ratio deduction. Using moderate input powers, wavelength conversion is achieved over a 17-nm (2-THz) range, with 0.7-3-dB power penalties     

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     

Cascaded wavelength conversion by four-wave mixing in a strained semiconductor optical amplifier at 10 Gb/s

We demonstrate for the first time cascaded wavelength conversion by four-wave mixing in a semiconductor optical amplifier. Bit-error-rate performance of <10/sup -9/ at 10 Gb/s is achieved for two conversions of up to 9 nm down and up in wavelength. For two wavelength conversions of 5 nm down and up, a power penalty of 1.3 dB is measured. A system of two wavelength converters spanning 40 km of single-mode fiber is also demonstrated.     

20 Gbit/s wavelength conversion using semiconductor nonlinearity

A polarisation insensitive wavelength conversion of 20 Gbit/s data signals over a range of 12 nm has been demonstrated using nonlinear processes (cross-phase modulation) in a travelling wave semiconductor laser amplifier and a polarisation nulling technique     

10 Gb/s wavelength conversion with integrated multiquantum-well-based 3-port Mach-Zehnder interferometer

All-optical wavelength conversion of 10 Gb/s data with simultaneous regeneration of the extinction ratio is achieved by means of a monolithic 3-port Mach-Zehnder interferometer. The reported devices are based on an all active multiquantum-well waveguide structure with optical amplifiers in the input/output gates. Wavelength conversion is realized by optical cross-phase modulation in a counter propagative operation mode without applying an optical filter. The 3-port Mach-Zehnder interferometer can provide either inversion or noninversion of wavelength converted 10 Gb/s data.     

Hybridization platform assembly and demonstration of all-optical wavelength conversion at 10 Gb/s

The development of a high-performance hybrid integration platform is demonstrated using an all-optical wavelength converter based on an integrated semiconductor optical amplifier (SOA) Mach-Zehnder interferometer (MZI). The device structure, transfer functions, power penalties and regenerative properties are presented for data rates up to 10 Gb/s.     

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     

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.     

Polarization-independent wavelength conversion at 2.5 Gb/s by dual-pump four-wave mixing in a strained semiconductor optical amplifier

We give a general expression for the polarization dependence of the four-wave mixing (FWM) efficiency in the dual-pump configuration. This expression, along with some general properties of the FWM susceptibility tensor, is used to propose a simple scheme to generate a nearly (1.5-dB variation) polarization independent FWM converted signal. The viability of this scheme is verified in a wavelength conversion experiment at 2.5 Gb/s.     

80 Gbit/s wavelength conversion using semiconductor optical amplifier and optical bandpass filter

A wavelength converter is presented that is made out of a semiconductor optical amplifier and an optical bandpass filter. Error-free inverted wavelength conversion is demonstrated at a bitrate of 80 Gbit/s. This approach can be exploited at higher bitrates. A clear open eye indicating error-free wavelength conversion at 160 Gbit/s is also presented. This wavelength converter has a simple configuration and allows photonic integration.     

Chirp reduction of directly modulated semiconductor lasers at 10Gb/s by strong CW light injection

The influence of strong light injection on the reduction of the dynamical linewidth broadening of directly current-modulated semiconductor lasers at high bit rates is theoretically investigated and experimentally verified for 10 Gb/s NRZ pseudorandom modulation with a large current swing of 40 mA pp. Significant chirp reduction and single-mode operation are observed for bulk DFB, quantum well DFB lasers at 10 Gb/s and a weakly coupled bulk DFB laser at 8 Gb/s, so that an improvement of the transmission performance using standard monomode fibers in the 1.55 μm low-loss wavelength region can be achieved for all these laser types, where dispersion otherwise causes severe penalties for long-haul transmission. The properties of injection-locked bulk DFB and quantum well DFB lasers with respect to high bit rate modulation have been systematically studied by the use of the rate equation formalism. A dynamically stable locking range of more than 30 GHz under modulation has been found for both laser types with injection ratios higher than 0.5     

Transmission performance analysis of 8/spl times/10 Gb/s WDM signals using cascaded SOAs due to signal wavelength displacement

We have analyzed the transmission performance of 8/spl times/10 Gb/s wavelength division multiplexing (WDM) signals due to crosstalk in cascaded conventional semiconductor optical amplifiers (SOAs). Using two different methods, the crosstalk over the whole gain bandwidth in SOAs is calculated to be 2-5 dB lower for the positive detuning. Then, transmission performance of 8/spl times/10 Gb/s WDM signals up to 6/spl times/40 km span in terms of receiver sensitivity is estimated over various transmission distances using cascaded SOAs for the positive signal wavelength displacement of 30, 40, and 50 nm. Especially for 50 nm detuning, transmission performances with and without using a reservoir channel are similar to each other. Our results suggest that SOAs can be used as an optical amplifier for displacement larger than 50 nm without using the reservoir channel.     

Wavelength conversion up to 18 nm at 10 Gb/s by four-wave mixing in a semiconductor optical amplifier

We characterize the conversion bandwidth of a four-wave mixing semiconductor optical amplifier wavelength converter. Conversion of 10-Gb/s signals with bit-error-rate (BER) performance of <10/sup -9/ is demonstrated for wavelength down-shifts of up to 18 nm and upshifts of up to 10 nm.     

Wavelength shift keying modulation up to 35 Gb/s with wavelength tone reuse to multiplex two 40 Gb/s DPSK signals

Fast optical frequency shift keying or wavelength shift keying (WSK) modulation offers advantageous features for applications in long haul communications and in optical labeling for packet routing. This includes simple demodulation by optical filtering and constant amplitude envelope providing tolerance to fiber nonlinear effects during transmission. In this paper we report on the generation of WSK signals up to 35 Gb/s with reuse of the wavelength tones for polarization multiplexing two independent 40 Gb/s DPSK signals. Transmission over a 50 km fiber link of the resultant three channel signal is also reported.     

光纤环形腔半导体激光器全光波长转换特性分析

提出了一种基于光纤环形腔半导体激光器的全光波长转换方案。利用稳态速率方程,导出了激光器有源区载流子密度与偏置电流及输入信号光功率关系的隐函数表达。从而研究了待转换的信号光及偏置电流对转换光功率和消光比的影响。     

半导体激光器波长转换中的噪声抑制

利用可调谐外腔半导体激光器进行了波长转换实验。静态转换后的波长可以在６０ｎｍ范围内连续调谐,并实现了１５５Ｍｂ／ｓ和６２２Ｍｂ／ｓ速率信号的动态波长转换。对激光器型波长转换器的噪声传输特性进行了研究,分析表明,由于输入和输出存在阈值特性,因此可以有效地抑制输入信号“１”上的噪声,波长转换对噪声性能的改善和输入光的功率和噪声带宽有关。     

Observation of phase conservation in a pulse sequence at 10 Gb/s ina semiconductor optical amplifier wavelength converter by four-wavemixing

Phase conservation in a pulse sequence at 10 Gb/s in wavelength conversion by four-wave mixing in a semiconductor optical amplifier is experimentally demonstrated. Conversion of 10-Gb/s signals with a bit-error rate of <10^-9 is demonstrated for wavelength downshifts of 12.5 nm