Passively Q-switched ytterbium-doped ScBO3 laser with black phosphorus saturable absorber

We demonstrate a passively Q-switched Yb 3+ -dopedScBO 3 bulk laser using a black phosphorous (BP) saturable absorber, a two-dimensional semiconductor. The response spectra of BP show that it is suitable as a universal switcher in the spectral range from the visible to midinfrared band. Considering the saturable absorption properties of BP and emission properties of Yb 3+ -doped crystals, the passively Q-switched bulk laser pulses were realized with the Yb 3+ :ScBO 3 crystal as a gain material and a fabricated BP sample as a Q-switcher. Because of the large energy storage capacity of Yb 3+ :ScBO 3 , the maximum output energy is obtained to be 1.4   μ J , which is comparable with the previous reported maximum energy of graphene Q-switched lasers. The obtained results identify the potential capability of BP as a pulse modulator in bulk lasers, and BP plays an increasingly important role in a wide range of its applications, including photonics and optoelectronics.