Testbed for System Level Characterization

In order to fully evaluate the performance of optical and electrical subcomponents for optical transmission systems, they need to be tested in a real system environment. Fraunhofer HHI offers well-equipped, system laboratories to perform such tests, providing state-of-the-art and beyond WDM transmission system infrastructure to generate and receive various modulation formats (BPSK, QPSK, M-QAM, 4D-formats, …) at high symbol rates up to 100 Gbaud.

All kinds of subcomponents can be characterized and tested, ranging from single devices like balanced photodetectors, modulators, electrical driver amplifier, optical amplifier (EDFA, SOA, Raman, Parametric Amplifier) or transmission fiber (standard single-mode fiber, pure-core silica fiber, large effective area fiber) up to complete sub-systems like coherent optical receiver or dual-polarization QPSK transmitter.

Back-to-back measurements

• Back-to-back configuration (direct connection between Transmitter and Receiver)
• Eye / Constellation Diagramms
• Optical / Electrical Spectra
• Bit-error ratio / Error vector magnitude

Transmission experiments

• Transmission over up to 1000 km straight line
• Eye / Constellation Diagramms
• Optical / Electrical Spectra
• Bit-error ratio / Error vector magnitude

Long-haul transmission experiments

• Transmission over long-haul distances (several thousand km) in a recirculating loop
• Eye / Constellation Diagramms
• Optical / Electrical Spectra
• Bit-error ratio / Error vector magnitude

• Measurements under variation of different parameters (OSNR, span length, transmission distance, fiber type, fiber input power, accumulated dispersion, …)
• Recirculating loop setup to cover distances from a few km up to several thousand km
• Test of DSP algorithms