Data transport via fibre-optic network could be faster still

An existing technology for increasing the bandwidth is 'wavelength division multiplexing' (WDM). In this approach the electrical data signals modulate different colours of light, which are combined in a single optical fibre. An alternative for WDM is combining several optical signal streams into a single stream of short pulses of a single colour of light: 'optical time division multiplexing' (OTDM).

Verdurmen' s research focused on the adding and extraction of a specific data stream from an OTDM signal. The component that performs this function is a so-called add-drop multiplexer (ADM). These ADMs can be subdivided into two categories. The first category is based on solutions that make use of semiconductor structures and the second category makes use of the nonlinearity of an optical fibre.

The application of the ADM technology on the basis of semiconductor material encountered the problem that the necessary higher input capacity led to a faster signal response but also a deterioration in the signal-noise ratio. The study therefore focused on ADMs that use the nonlinearity of optical fibres.

The advantage of using the nonlinearity of the optical fibre turned out to be an ultrafast response time. As a result of this Verdurmen succeeded in producing an ADM with a speed of 320 gigabits per second. According to Verdurmen, combining WDM and OTDM will lead to even higher speeds still in the future.

Source: NWO