Atom–light interface is at the core of quantum metrology and quantum information science. Associated noises during interaction processes are always inevitable and adverse. In this paper, we perform the stimulated Raman scattering (SRS) in a hot Rb87 vapor cell and demonstrate the reduction of related noises originated from mode mismatch via optimizing the temporal waveform of the input seed. By using the seed with the optimized mode, the intensity fluctuation of the signal field generated in atom–light interaction is decreased by 4.3 dB. Furthermore, the fluctuation of the intensity difference between the signal and atomic spin wave is reduced by 3.1 dB. Such a temporal mode-cleaning method can be applied to improve the precision of atom interferometry using SRS and should be helpful for quantum information processing based on an atom–light correlated system.