Optical millimeter-wave generation and transmission system for 1.25 Gbit/s downstream link using a gain switched laser

In this paper, we propose a novel and cost effective system for optical millimeter-wave (mm-wave) generation and transmission of downstream data based on a gain switched laser (GSL). The GSL produces an optical comb spectrum that can be appropriately filtered to generate two optical sidebands spaced by more than 4 times the repetition rate of the GSL. These sidebands are modulated by baseband data and then transmitted via optical fiber to the remote antenna unit (RAU). At the RAU, the two sidebands are heterodyned using a photodetector to generate the electrical modulated mm-wave signal, before demodulation using self mixing. We demonstrate the distribution of 1.25 Gbit/s data OOK modulated onto a 60 GHz carrier, similar to that used in the IEEE 802.15.3c draft standard, over fiber lengths up to 62 km.