AgScP2S6 van der Waals Layered Crystal: A Material with a Unique Combination of Extreme Nonlinear Optical Properties

Research in two-dimensional layered materials (2DLMs) has exploded over the past several years for a variety of applications in photonics and optoelectronics. The 2D nature of these materials allows for a very local electronic probe of material as well as flexible integration with other functional components. Herein, using the femtosecond Z-scan technique, we report a giant two photon absorption (TPA) process and its saturation in the van der Waals gapped silver scandium thiophosphate (AgScP2S6) crystal. We have found a TPA coefficient of the order of 104 cm/GW which is orders of magnitude larger compared to many existing semiconductors and nonlinear crystals. Furthermore, we found a TPA cross-section of 103 GM and characterized the optical limiting (OL) response (0.2 mJ/cm2) and the multipulse laser damage threshold (1.09 +/- 0.19 J/cm2). The combination of giant TPA, extremely low OL, and very high damage threshold suggests that this material could be extremely useful in applications like optical limiters or switches.

Automated summary

Research on two-dimensional layered materials (2DLMs) has grown rapidly in recent years due to their applications in photonics and optoelectronics. The unique 2D nature of these materials allows for localized electronic probing and flexible integration with other components. In this study, we used the femtosecond Z-scan technique to investigate the two photon absorption (TPA) process in the van der Waals gapped silver scandium thiophosphate (AgScP2S6) crystal. We observed a significantly higher TPA coefficient compared to traditional semiconductors and nonlinear crystals, indicating the potential usefulness of this material in optical limiters and switches.