Optical Single Sideband Modulation With Tunable Optical Carrier-to-Sideband Ratio

A novel approach to realize optical single sideband (OSSB) modulation with tunable optical carrier-to-sideband ratio (OCSR) is proposed and demonstrated based on cascaded polarization modulators (PolMs). In the proposed scheme, OSSB polarization modulation is first obtained by driving two cascaded PolMs with two RF signals that are 90 ° out of phase. Then, by placing a polarizer after the PolMs, an OSSB-modulated signal with a tunable OCSR is obtained by adjusting the polarization direction of the polarizer. An experiment is carried out. An OSSB signal with a tunable OCSR from -26 to 46 dB is achieved. The operation bandwidth covers the frequency range of 5-35 GHz.