Generation of a vector conventional soliton via a graphene oxide saturable absorber

We have experimentally observed an ultrashort conventional vector soliton in an erbium-doped fiber laser. The few-layered graphene oxide (GO) is used as a saturable absorber (SA). It is found that the saturable absorption characteristic of GO is polarization independent. Therefore, vector solitons can be obtained without polarization control by using such SA. By using a polarization beam splitter to split the mode-locked pulse obtained in the oscillator, two orthogonal polarization vector solitons with equal intensity and consistent characteristics can be obtained. It demonstrates that the initial soliton consists of two orthogonal polarization components. It is worth noting that these two orthogonal polarization component solitons improve the signal-to-noise ratio (SNR) of 3 dB compared with the initial soliton. The improvement in SNR is very significant and cannot be neglected. This phenomenon has not been reported before, to our knowledge. In addition, the conventional soliton generated by this mode-locked laser has a central wavelength of 1559 nm with 1.1 ps pulse duration. The mode-locking state of this laser can be self-started. After mode locking, the environmental stability is excellent. The experimental results indicate that GO as a broadband SA has great potential and application prospects in the field of vector soliton generation.