R.J.S. Pedersen

All optical wavelength conversion by SOA's in a Mach-Zehnder configuration

Penalty free wavelength conversion is demonstrated at 2.5 Gbit/s over a wavelength span of 12 nm by the use of semiconductor optical amplifier (SOA)s in a Mach-Zehnder configuration. An increase in the extinction ratio is measured for the converted signal compared to the input signal implying signal regeneration as well as wavelength conversion.<<ETX>>

Input power limits and maximum capacity in long-haul WDM lightwave systems due to stimulated Raman scattering

Abstract A new accurate expression is derived to evaluate input power limits and maximum capacity for an amplitude (or intensity) modulated WDM lightwave system only considering the effect of SRS. The maximum limits of input power and capacity are obtained for such a system.

Wavelength conversion devices

Summary form only given. Wavelength converters will be essential devices to exploit the full potential of the wavelength dimension in wavelength-division multiplexed (WDM) networks. Based on experiments, we discuss different candidates for efficient wavelength converters with attention to expected system requirements. The ideal wavelength converter should be transparent to the bit rate and signal format and provide an unchirped output signal with both a high extinction ratio and a large signal-to-noise ratio. It should allow conversion to both shorter and longer wavelengths with equal performance and operate at practical input power levels.

Transmission performance through cascaded 1-nm arrayed waveguide multiplexers at 10 Gb/s

The transmission properties of cascaded arrayed waveguide multiplexers are examined in a recirculating loop experiment. We show that a cascade of 40 multiplexers each with 3-dB bandwidth of /spl sim/1 nm can be passed penalty-free at 10 Gb/s. Furthermore, we show that the allowable fluctuation of the center frequency for a 10 Gb/s signal is reduced to 24 GHz at bit-error rate (BER)=10/sup -9/ for a concatenation of 40 multiplexers.

New types of 2 x 2 wavelength-switching blocks for optical cross-connects

Two types of modular 2/spl times/2 wavelength-switching blocks are proposed in this letter. A 2/spl times/2 fixed wavelength-switching block can cross-connect two fixed channels between two fibers, and a 2/spl times/2 tunable wavelength-switching block can cross-connect any two channels between two fibers. These modular blocks can be used to build scalable multiwavelength cross-connects in optical networks.

Novel 2/spl times/2 multiwavelength optical cross connects based on optical add/drop multiplexers

A novel architecture of 2/spl times/2 multiwavelength optical cross connects based on optical add/drop multiplexers and optical switches is described. The structure is strictly nonblocking with a high degree of modularity. Its basic performance is experimentally demonstrated.

Extinction ratio effect for high-speed optical fiber transmissions

In conventional optical transmissions, the extinction ratio is expected to be as high as possible in order to get better receiver sensitivity. But for high-speed long distance optical transmissions, the system performance is mainly dependent on the self-phase modulation (SPM) when the input optical power is sufficiently high. It is possible that a large improvement of the receiver sensitivity can be obtained by using an input signal with finite extinction ratio when the SPM takes effect. In this paper, the interaction of the fiber dispersion, SPM, prechirp and extinction ratio is investigated and the optimisation of system performance is implemented for a 10 Gbit/s long distance unrepeatered unregenerate optical transmissions.

Fully reconfigurable 2x2 optical cross-connect using tunable wavelength switching modules

Wavelength division multiplexing (WDM) not only increases fiber transmission capacity but also simplifies network operation by introducing the . optical path layer concept 111. Multi-wavelength optical cross-connects (OXC) are key elements in reconfigurable WDM networks.

Wavelength conversion based on cross-phase modulation in a semiconductor Mach-Zehnder modulator

Wavelength conversion based on cross-phase modulation in a reversely biased semiconductor Mach-Zehnder modulator is proposed and successfully demonstrated in a commercial device. The converted signals exhibit extinction ratio >13 dB and penalty <1.5 dB at 10 Gb/s for both NRZ and RZ formats.

Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

Summary form only given.Interferometric crosstalk is one of the biggest issues in transparent wavelength-division-multiplexing networks, and should be overcome by either decreasing the crosstalk level from the components, or employing effective techniques to suppress its impact. We use a gain-saturated semiconductor optical amplifier to suppress the impact of interferometric crosstalk, and show that 6 dB more crosstalk can be tolerated for 1 dB penalty at 10 Gbit/s. Using polarization multiplexing of optical signals modulated by data and the complementary, impairments such as waveform distortion and extinction ratio degradation are eliminated, and the method is also bit rate transparent.