Abstract This work outlined the integrated role between vertical cavity surface emitting laser diodes with Gaussian pulse generators and Ideal erbium doped fiber amplifier (EDFA) for the self-phase modulation instability management, as well as the signal/NP level (Power level [PL]) with the spectral frequency is simulated after wavelength division multiplexing (WDM) fiber at length of 10 km based third order Gaussian pulse generators. The light power variations against temperature after WDM fiber is also studied at length of 10 km based various order Gaussian pulse generators. Electrical received power (ERP) variations against temperature is clarified after avalanche photo diode (APD) photodetectors based various order Gaussian pulse generators. The study emphasis the bad effects of the increase of the temperature, and higher Gaussian pulse generators order on the signal power levels.