Tunable dual-wavelength saturable absorber based on dual defective photonic crystal by MoS2 monolayer

Dual-wavelength Q-switched lasers have currently received extensive attention due to their wide applications in nonlinear optoelectronic devices. Their main mechanism can be based on the integration of laser with devices such as dual defective photonic crystals (DPCs). Nonetheless, DPCs with a high modulation depth is still demanding in this field. Toward this goal, in this paper, we have designed a dual DPC with MoS2 monolayers as defects in this structure. Defect modes helped adjust the wavelength by the distance between the two defects, and finally, a tunable wavelength was created by changing the intensity, incident angle, and polarization. Using the dual DPC, modulation depth was increased to 97% and 85% in the dual defect modes and a wide range of light intensities was achieved with over 80% of absorption, which helps accomplish a tunable dual Q-switching operation. •Defect photonic crystals with two defects containing MoS2 monolayer.•The development of a dual-wavelength tunable saturable absorber.•The nonlinear phenomenon is observed as the incident light intensity is increased.•Increased modulation depth to 99% and created a wide range of incident light intensity with over 80% of absorption.