High-Speed TDM-Systems

The High Speed TDM Systems Group at HHI (OTDM-group) investigates high speed data transmission systems with data rates over 40 Gbit/s.

Presently, the only technology to generate such high data rates is Time Division Multiplexing (TDM). As current electronics is limited to ~50 Gbit/s, Optical Time Division Multiplexing (OTDM) is used in the laboratory, taking advantage of short pulse generation in the optical domain. Different data signals with a low data rate of e.g. 40 Gbit/s and a short pulse width of a few ps, are bitwise interleaved in the time domain to create a high-bitrate signal of e.g. 160 Gbit/s. In contrast to wavelength division multiplexing (WDM), only one wavelength ("color") of light is used.

Our research activities cover the following topics:

• Components for Receiver and Transmitter based on OTDM (MUX, DEMUX, Clock Recovery)
• Long-term stable transmission systems using different  modulation formats (e.g. ASK, DPSK, DQPSK, ...)
• Monitoring (optical sampling) techniques
• Compensation techniques (PMD, CD compensation)
• Signal Processing using SOA's, functional fibers and PPLN (wavelength conversion, regeneration, add-drop multiplexing, ...)

We have a world-leading testbed for high speed data transmission up to 320 Gbit/s. We offer measurements on high-speed components with cutting-edge measurement equipment and we offer the components for upgrading your 10 or 40 Gbit/s transmission system to 160 Gbit/s.The group presently holds the world record in high speed transmission after having demonstrated single-channel 2.5 Tbit/s transmission over a 160 km fiber link together with Fujitsu Laboratories Ltd, Japan, in 2005. If our portfolio attracts your attention, please feel free to contact us at any time by sending an email. Your email will be answered within 1-2 working days.