In this work, we report the use of self-phase modulation in a high nonlinearity fiber for super continuum frequency generation which is spectrum-sliced using a demultiplexer. Four channels (193-193.225 THz) are sliced with 75 GHz channel spacing. Each wavelength channel transports two distinct sub-channels with 20 Gbit/s-40 GHz data rate over different Laguerre Gaussian spatial modes (LG02 and LG03) using the proposed hybrid spectrum sliced-wavelength division multiplexing-mode division multiplexing based orthogonal frequency division multiplexing-radio-over-free space optics link. The performance of the proposed link is investigated using numerical simulations. 160 Gbit/s-320 GHz data is transmitted at 20 km for clear conditions with reliable performance. We have also analyzed the link performance under different level of fog weather. Further to maximize the link reach, we have proposed an enhanced detection at the receiver terminal. The results of numerical investigation of the link show an improvement of 40 dB in signal-to-noise ratio and received power under different weather conditions using the proposed detection technique.