Optical wavelength conversion system developed

1 min read

Fujitsu Laboratories and Fraunhofer’s Heinrich Hertz Institute (HHI) have developed a way to simultaneously convert the wavelengths of multiplexed signals in wavelength division multiplexed systems and have tested the approach by transmitting data at 1Tbit/s.

According to the partners, in conventional optical wavelength conversion systems, each optical wavelength is converted into an electrical signal, then retransmitted at a new wavelength. This is said to be impractical for terabit class processing as each wavelength requires its own opto to electrical to otpo circuit. With the new systems, optical wavelength conversion and polarisation state are controlled at the same time, so simultaneous wavelength conversion of wideband optical signals can be achieved without restrictions on the wavelengths of the optical input signal or the modulation formats.

The two components of the optical signal consist of vertically and horizontally polarised waves. By separating them, performing the wavelength conversion in parallel, then recombining the signal, the partners have demonstrated simultaneous conversion of polarisation multiplexed signals running at more than 1Tbit/s, using a prototype circuit.

As a result, say the partners, processing can be achieved with a single wavelength converter, regardless of the number of wavelengths multiplexed.

With optical signals carrying data at rates in excess of 1Tbit/s and multiplexed from 10 wavelengths, for example, the new method can process them using 10% of the power required by previous technologies. In addition, because there are no restrictions on the wavelengths before or after conversion, the approach is said to enable flexible next generation optical networks.