Researchers in Japan have developed a small silicon optical modulator, a device that converts electrical signals into light signals. It transmitted data at up to 200 gigabits per second. The design could help AI data centres, which need to move huge amounts of information between chips without increasing energy use.
A carefully arranged pattern of tiny holes slows the light inside the device. This makes the light interact more strongly with the silicon, allowing small electrical changes to produce larger changes in the light signal. However, electrical resistance normally limits how quickly slow-light devices can respond. The researchers addressed this with a built-in equaliser, which adjusts how parts of the light signal combine. With additional signal correction at the receiving end, the device reached its highest transmission rate. Its total length is 320 micrometres, compared with several millimetres for conventional devices.
The smaller design could allow more light-based connections in data centres while helping to limit energy consumption. However, it still loses a considerable amount of light. The team used an optical amplifier to strengthen the signal during experiments. Researchers also plan to widen the range of wavelengths it can handle, potentially allowing several data channels to operate together. This combined operation remains a future possibility.
