Simultaneous generation of wavelength multiplexing and polarization multiplexing from a wavelength-tunable ultrafast fiber laser

A wavelength-tunable mode-locked erbium-doped all-fiber laser delivering both wavelength multiplexing and polarization multiplexing asynchronous pulses is experimentally demonstrated, which is challenging in previous studies. The numerical simulations validate the experimental observations and reveal that the cavity birefringence and polarization dependent loss (PDL) induced by the wavelength division multiplexer play a significant role in the formation of different types of asynchronous pulses. Our results not only provide insights into the physical mechanism of the asynchronous pulses generation, but also offer a potential low-complexity light source for dual-comb applications.