Comparison of the Noise Penalty of a Raman Amplifier Versus an Erbium- doped Fiber Amplifier for Long-haul Analog Fiber-optic Links

摘要

A Raman amplifier is compared to an erbium-doped fiber amplifier for a 14 km analog fiber-optic link requiring the amplifier pump at the end of the link. The noise penalty for each amplifier at a given photocurrent is measured and compared. An analytical expression comparing the analog metrics as a function of noise penalty and photocurrent for different amplifiers is derived and used. The Raman amplifier has a lower noise penalty performance for a long- haul analog fiber-optic link versus an erbium-doped fiber amplifier placed at the end of the link. The best compromise comes from a hybrid amplifier, which combines the Raman amplifier with the erbium-doped fiber amplifier and offers the best RF performance while taking only a minimal penalty on the RF noise figure and spurious free dynamic range.