Routers for trunk telecommunication systems currently operate at 2.5 Gb/s. Next generation routers will be required to switch 128 input data streams into 128 output data streams, each data stream being at a data rate of 10 Gb/s. Current routers employ massively parallel electronic switches to route data at 1.25 Gb/s. Such technology is reaching its limit and a new approach to high-speed switching is required. The present invention provides an apparatus and method for enabling such high-speed switching by providing a data compression apparatus which comprises a pulsed chirped laser (226) coupled to a modulator (218, 220), the modulator (218, 220) being coupled to a compressor (228, 230). A chirped laser pulse having the duration of a data packet is modulated with data received on an input channel and then passed through the compressor (228, 230) in order to generate a compressed modulated data pulse for high speed switching.