Fig. 1. Schematic diagram of demonstrated WDM VLLC system including transmitters, cage systems and receivers

Fig. 2. Circuit of the Zobel pre-equalization network

Fig. 3. Amplitude-frequency response curve of designed Zobel pre-equalization network

Fig. 4. Experimental setup of high-speed WDM VLLC system. (a) Experimental setup diagram; (b) photo of the transmitter; (c) overall system photo; (d) photo of the receiver

Fig. 5. Frequency spectrum of transmitted signal and received signal. (a) Without pre-equalization; (b) with pre-equalization; (c) estimated SNR with or without pre-equalization

Fig. 6. Relationship between data transmission rate with and without pre-equalization and signal V_pp at different wavelengths. (a) 486.8 nm; (b) 517.7 nm; (c) 638.6 nm

Fig. 7. Bit allocation, SNR response, and the received constellation diagram for different wavelengths. (a) 486.8 nm; (b) 517.7 nm; (c) 638.6 nm; (d) loaded power ratio of each subcarrier in corresponding Figs. (a)‒(c)

Fig. 8. 40 channel WDM VLLC system. (a) Spectra; (b) data rates and BER (BER threshold is 3.8×10^-3)