Amplified Spontaneous Emission in Coherent Receivers - Impact & Mitigation

As we are aware that amplifiers suffer from ASE(amplified spontaneous emission)the OT(optical transponders) also suffer from ASE due to the phenomenon of light amplification by stimulated emission of radiation .So in a network the OTs having high ASE can impact other channels OSNR .We can mitigate their impact on other channels if they are patched to coloured Mux/Demux .The impact on OSNR is maximum when High noise OTs are patched to colorless Mux/demux .

The sole reason to this is colorless ports are not bandwidth filtered whereas colored ports are . .