**4. Conclusions**

We investigate experimentally and theoretically an all‐optical switch based on the SRS and demonstrate its viability. The use of SRS to design an all‐optical switch circuit makes it pos‐ sible to use very low powers of signal to control respectively strong pulses. The best con‐ trast (the ratio of signal energy at the output when the input signal is ON/OFF) was 15 dB in pump peak power of 6 W and input signal only of 0.5 mW. Since there is a big dif‐ ference between the wavelengths of pumping and signal, the walk‐off between pump and Stokes is inevitable. We investigate the possibility to avoid degradation of circuit operation by the walk‐off effect connecting fibers with normal and anomalous dispersion. We found that fibers with anomalous GVD effect of the MI and the breaking pulse appear lower than those required for a strong Raman amplification powers. We propose to use the spectral filter large bandwidth between states of Raman circuit for reducing problems of breaking pulses. We have built a simple configuration of the device with efficient switching and low power pump. Therefore, the experimental setup is compact and can be carried to another labora‐ tory, and results are repeatable, i.e., the measurements are not dependent on environmental parameters.
