Four-wave mixing in intra-cavity dual-wavelength fibre ring laser

An intra-cavity four-wave mixing (FWM) in a dual-wavelength erbium-doped fibre ring laser has been demonstrated where a 100 m-long dispersion-shifted fibre has been introduced as a nonlinear medium to pronounce the FWM effect in a 1550 nm window. The laser operates in the gain switched (pulse) mode for effectively achieving high power and increasing the intermodulation effect in the ring cavity. This scheme provides a simple and efficient way of archieving a dual-wavelength source for various optical systems.