RFoF solutions are made of 2 modules. The Tx module takes in the RF signal and via a modulation and laser converts it to an optical signal which can have a wavelength of 1310 nanometers or 1550 nanometers depending on the laser type used. At the far end, the Rx module takes in the optical signal and converts it back to RF signal which then can be connected to a receiver. This is known as the direct modulation method.
Another method is the indirect modulation, where the RF signal is modulated by an external Mach Zehnder modulator and is then converted back again. This method is used for high frequency applications from 8 GHz up to 40 GHz.