Hybrid MMW-over fiber/OFDM-FSO transmission system based on doublet lens scheme and POLMUX technique

•Propose and verify MMW-Over fiber and OFDM based FSO transmission system.•Doublet lens scheme greatly enhances the transmission distance (500 m) of FSO link.•Generate 60-GHz millimetre wave employing phase-modulator due to stable and bias free operation.•Filter or wavelength separator is not required because light-wave is separated employing polarizing effect.•Both LNA and CDR scheme suppress amplitude and phase-fluctuation of signal at receiving end.•Low BER < 10−8 and EVM < 12.3%, clear eye diagrams and constellation diagram are observed.