Characterization of SnSe2 saturable absorber by THz-TDS and used in dual-wavelength passively Q-switched laser

We firstly used THz-TDS to characterize the 2D-material (SnSe2) saturable absorber (SA) with nondestructive and high resolution. In addition, the application of the SnSe2 SA for dual-wavelength Q-switched laser is demonstrated. The highest dual-wavelength output power of 438 mW with the optical to optical efficiency of 9.7%. The minimum pulse width is 237 ns at the repetition rate of 72 kHz can be obtained. This results indicate that the THz transmission spectrum could be used to characterize the SAs and the tin diselenide SA also shows good features used in dual-wavelength solid state lasers.