Optical Techniques for Up-Conversion of MB-OFDM Signals in 60 Ghz Band Using Fiber Bragg Grating

We have demonstrated two techniques for all optical frequency up-conversion of Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) signal with 400 Mbps bit rate in the 60 GHz band. The first technique is based on direct modulation of Laser Diode (LD) associated with an electro-optic modulator (EOM) and the second one is based on two cascaded EOMs. For both techniques, a fiber Bragg grating (FBG) is inserted to suppress undesired signal around 60 GHz band. Direct modulation of LD with an EOM is cost effective compared to two cascaded EOMs, and exhibits a gain of 5 dB in the received optical power. A minimum error vector magnitude (EVM) of 18% and 20% are measured for direct modulation of LD with an EOM and two cascaded EOMs techniques, respectively which complies with MB-OFDM standard.