Kaspar Dütting

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.

The Y-laser: a multifunctional device for optical communication systems and switching networks

This paper gives a comprehensive review of the recent progress obtained with various operation modes of a Y-shaped all active waveguide device with three optical input/output ports, the so called Y-laser. Used as a monolithic semiconductor light source, single-mode emission with an extremely large cw tuning range of more than 50 nm is accessed. Single current step tuning spans up to 8-nm range. Several-GHz bandwidth AM and FM response is achieved. Operation as a wavelength processing device is demonstrated with data-stream transformation from short wavelength fiber windows (around 780 nm or 1310 nm) to the long wavelength window (1550 nm), as well as with ultra wide range wavelength conversion within the 1550-nm region, across +/-20 nm (blue and red shift). Optical high-speed space switching/gating functions are verified up to 1 Gb/s, and packet switching of 5-Gb/s data streams is demonstrated. Further features as a pulse reshaping device, as an electrically triggerable wavelength bistable device and as a mode locked pulse generator are addressed. Possible applications of this multifunctional device in future optical communication systems and switching networks are discussed. >

6 THz range tunable 2.5 Gb/s frequency conversion by a multiquantum well Y laser

Improved monolithic interferometric semiconductor lasers in Y configuration are reported. When they are operated as electrically tunable light sources, single-longitudinal-mode emission with a very large CW tuning range up to 51 nm is obtained. By using all-quaternary compressively strained multi-quantum-well (MQW) active layers, low DC threshold currents down to >

Selective MOVPE of semi-insulating InP layers for high speed OEICs

Abstract MOVPE growth on patterned substrates and doping behaviour of iron in InP were studied at different reactor pressures. The key parameters for a successful control of selective MOVPE like the growth temperature, growth rate, reactor pressure and the ratio of coated to uncoated surface are discussed. Dry and wet chemical etched structures were overgrown to get basic information for designing high speed OEIC structures. For low pressure growth, a reduced Fe incorporation and a drastically lowered diffusion tendency towards the layer/substrate interface was observed by SIMS profiles in contrast to atmospheric pressure growth as well as a strong interaction between zinc and iron regarding diffusion behaviour.

Analysis and simple tuning scheme of asymmetric Y-lasers

We present an analysis of interferometric lasers in Mach-Zehnder configuration with emphasis on the recently realized asymmetric Y-laser, leading to simple design and tuning rules. By tailoring the Mach-Zehnder (MZ) filter function we obtain a large variety of designable channel spacings together with improved sidemode suppression and easy access for wavelength division multiplexing (WDM) functions and wavelength conversion. >

Realization and wafer test of InGaAsP/InP DFB laser/monitor OEICs

Wafer-testable distributed feedback (DFB) lasers and monolithically integrated monitor diodes are realized to replace the time consuming and expensive single-chip test procedure in semiconductor laser fabrication process. Laser-end facets and integrated monitor diodes are defined on 1.5- mu m InGaAsP/InP multiple quantum well (MQW) DFB laser wafers by reactive ion beam etching (RIBE). Using terminal electrical noise (TEN) measurement, the lasers are characterized directly on the wafer with respect to threshold current and single mode operation. Threshold currents down to 10 mA have been achieved for the integrated devices.<<ETX>>