M. Dulk

All-optical space switches with gain and principally ideal extinction ratios

Asymmetric Mach-Zehnder interferometer (MZI) configurations are proposed to build all-optical space switches with gain and principally ideal extinction ratios. Actually, three asymmetries in MZI configurations with semiconductor optical amplifiers (SOAs) on their arms are discussed. The asymmetries in the all-optical switches are necessary to overcome the extinction ratio limitations that are due to the disturbing gain changes that arise when control signals are introduced into the SOAs to induce the necessary refractive index change for switching. Starting from a generic MZI configuration with SOAs on the arms, a description in terms of transmission matrices is used and applied to identify 1/spl times/2 and 2/spl times/2 all-optical switch configurations with high on-state transmissions and close to ideally large extinction ratios. The theoretical predictions are verified and found to be in excellent agreement with experiments for a switch with symmetric MZI splitters in a monolithically integrated InP waveguide version that allows operation with equally or unequally biased SOAs.

All-optical Mach-Zehnder interferometer wavelength converters and switches with integrated data- and control-signal separation scheme

All-optical Mach-Zehnder interferometer (MZI) wavelength converters and switches with monolithically integrated data- and control-signal separation schemes are reported. Two schemes to separate the data from the strong control signals are discussed. A first dual-order mode configuration uses modes of different symmetry for the data and control signals. A second configuration uses additional MZIs to separate the two signals. The control-signal separation permits to operate the devices with copropagating data and control signal without distortion of the control signal in the data-signal output. Copropagative operation allows for shorter switching windows compared to the counterpropagative operation. Further, this concept enables cascading of several devices since the control signal is filtered out and does not disturb the signal processing in a next cascade of devices. The all-optical switches are characterized under static and dynamic 10 GHz conditions.

All-optical regenerative OTDM add-drop multiplexing at 40 Gb/s using monolithic InP Mach-Zehnder interferometer

We present a novel method for all-optical add-drop multiplexing having regenerative capability for 40-Gb/s optical time-division multiplexed (OTDM) data using a semiconductor optical amplifier (SOA) based, monolithic Mach-Zehnder interferometer (MZI). Simultaneous dropping of one 10-Gb/s channel out of 10-Gb/s OTDM data and perfect clearing of the corresponding time slot in the remaining 3/spl times/10 Gb/s data stream is demonstrated. Bit-error-rate measurements show a low penalty of 2 dB for each 10 Gb/s channel. No extra penalty was observed introducing a 10-Gb/s add channel through the device into the cleared time slot.

All-optical sampling with a monolithically integrated Mach-Zehnder interferometer gate.

An all-optical sampler consisting of a polarization-independent monolithic Mach-Zehnder interferometer with integrated semiconductor optical amplifiers and a temporal resolution of 1 ps is presented. As an example, a simple 320-Gbit/s pattern has been successfully sampled, demonstrating the functionality of this scheme for high-bit-rate waveform characterizations in light-wave systems.

Cascadable MZI all-optical switch with separate ports for data- and control-signals

Demonstration of a new all-optical space switch, with separate in- and output ports for the data- and control-signal. At 10 GHz the crosstalk between copropagating data- and control-signal exceeds 20 dB, making the device interesting for future cascadation and bidirectional operation on a single chip.

All-optical regenerative OTDM add/drop multiplexing at 40 Gbit/s using monolithic InP Mach-Zehnder interferometer

Summary form only given. Add-drop time multiplexing is a necessary function required in an optical time-division multiplexed (OTDM) network node. Perfect clearing of the time slot which corresponds to the drop channel should be performed in order to avoid interferometric crosstalk. Simultaneous add-drop multiplexing using a semiconductor optical amplifier (SOA) based Mach-Zehnder interferometer (MZI) has been previously performed. However the performance was limited by pattern effects after clearing and the compromise between either perfect clearing or dropping. We present a novel method which allows for simultaneous perfect dropping and clearing for 40 Gb/s OTDM signals using a monolithically integrated SOA-MZI. Further the proposed technique introduces regenerative capabilities at each add-drop node avoiding the cascadability limitation of OTDM add-drop nodes.

Wavelength conversion from C- to L-band at 10 Gbit/s including transmission over 80 km of SSMF

Summary form only given.As the need for capacity increases, means to accommodate the growth is getting increasingly important. Hence, higher bit rates and an ever increasing number of WDM channels is being employed. This has led to the introduction of the L-band (ranging from 1570 to 1610 nm) as the new transmission window, opening up for-in conjunction with the C-band-an astonishing 80 nm of available bandwidth. However, as the number of wavelength channels increases, the need for wavelength conversion is becoming ever more pronounced. To perform the wavelength conversion, interferometric structures such as the monolithically integrated Mach-Zehnder interferometers (SOA-MZI) using semiconductor optical amplifiers as phase-shifting elements have proven excellent candidates. Here we present the conversion and transmission properties of a fully packaged device capable of wavelength conversion from C- to L-band having more than 80 nm of wavelength conversion range.