In optical communication system, intensity noise is harmful to optical signal transmission and processing. For an instance, in wavelength-division-multiplexing (WDM) systems or passive optical network (PON), spectrum. In optical communication system, intensity noise is harmful to optical signal transmission and processing. For an instance, in wavelength-division-multiplexing (WDM) systems or passive optical network (PON), spectrum slicing is an attractive way as they use the cost-effective available incoherent optical source, such as the light-emitting diodes, super-luminescent diodes, and fiber-based amplified spontaneous emission (ASE) sources,. By spectrum slicing, only one broadband optical source is needed to form many channels by dividing the spectral slice to each channel. However, the optical signal-noise ratio (OSNR) suffers from the severe intensity noise of the broadband optical source.Another typical example is the super-mod. The enhanced performance for relative intensity noise (RIN) reduction based on reflective semiconductor optical amplifiers (R-SOA) has been investigated theoretically by comparison with conventional transmission SOA. The results show that, by selecting appropriate input optical power, as large as >20 dB RIN suppression improvement can be achieved for R-SOA, without sacrificing the noise rejection bandwidth. With increased injection current, the optimized input signal power is decreased and the operation region is extended for the best RIN reduction. For RIN suppression in WDM spectrum slicing, the bandwidth optimization of receiver filter should be performed to avoid the spectral broadening induced by self-phase modulation (SPM) and four wave mixing (FWM). Our derive. Reflective semiconductor optical amplifiers (R-SOA)Relative intensity noise (RIN) suppressionThe schematic diagram of RIN suppression based on R-SOA is shown in Fig. 1. The signal light with noise is launched into R-SOA via an optical circulator (OC). The tunable optical band-pass filter (BPF) is applied to exclude the ASE of R-SOA. The signal input power into R-SOA can be adjusted using a variable optical attenuator (VOA) to reach the opt. The device structure and material parameters used in simulation are listed in Table 1. In the following discussions, RIN suppression comparisons between convention transmission SOA and R-SOA will be discussed in detail. The parameters' optimization for the best RIN reduction is also shown.Table 1. Device structure and material parameters used in calculations.Fig.2 shows the comparisons on MTF ((a) and (b)), carrier density distribution ((c) and (d)), and optical power distribution ((e) and (f)) between R-SOA((a), (c) and (e)) and conventional transmission SOA ((b), (d) and (f)) for various signal input powers. In Fig. 2(e), the solid and dotted lines represent the forward and backward optic.