A laser diode has a threshold current of 12 mA and emits at 3 mW/mA rate. A diode current of 15 + 5sin ωt (mA) produces an optical signal, which is coupled into a SI fiber having a loss rate of 2-dB/km and a numerical aperture of 0.24. After 10-km propagation length, an erbium-doped fiber amplifier having a noise figure of 6 and a gain of 15 dB amplifies the signal. The signal output of laser has a 50-dB signal to noise ratio (SNR). Compute the signal power (in dBm) and signal to noise ratio (in dB) at the amplifier's output.