Integrated Optical Wavelength Converters and Parametric Amplifiers in Periodically Poled Lithium Niobate (PPLN)

• Applicant: Professor Dr. Wolfgang Sohler
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
• Term: from 2008 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 78169479

This project is part of a joint research programme of two Chinese groups at the Tsinghua- University (Beijing, China) and of three German groups (Fraunhofer-lnstitute for Telecommunications - Heinrich-Hertz-lnstitut, Technical University Berlin, University of Paderborn). Its overall objective is contention resolution in optical burst switching (OBS) networks by wavelength conversion.The objective of this sub-project is the development of ultra fast, modulation format transparent, polarization-dependent and polarization-insensitive, integrated all-optical wavelength converters and parametric amplifiers for fibre optical Wavelength Division Multiplexing (WDM-) communication systems using OBS. The devices take advantage of the high optical nonlinearity of periodically poled Lithium Niobate (PPLN) waveguides exploiting cascaded Second Harmonic Generation / Difference Frequency Generation (cSHG/DFG) and cascaded Sum Frequency Generation / Difference Frequency Generation (cSFG/DFG), respectively.Based on the results of the first project period, the work in the next two years will concentrate on four interdependent topics. The first is a further improvement of the waveguides with respect to nonlinear conversion efficiency and stability. The second is the optimisation of devices with configurations, identified within the 1st project phase as the most promising ones. This also includes a polarisation-insensitive set-up. These devices will be operated and characterized as (tuneable) all-optical wavelength converters for the third telecommunication window - the third topic. At higher pump power levels - and that is the fourth topic - net optical parametric amplification can be achieved. It will first be studied in a pulsed mode of operation. Depending on the waveguide properties also cw-operation should become possible.Specific wavelength converters and parametric amplifiers will be transferred to the project partner HHI for further characterization and investigation in high-speed phase-modulated fibre optical transmission systems.

• DFG Programme: Research Grants
• Participating Person: Dr. Hubertus Suche