Investigation of Nonlinear Optical Properties and Response Mechanisms in Monolayer ZrGeTe ₄

The excellent optoelectronic properties and quantum confinement effects exhibited by low‐dimensional semiconductor materials have garnered significant attention in frontier photonics research. Their applications as saturable absorbers for laser pulse modulation have been extensively studied. However, significant challenges remain in translating the potential of such materials into practical device performance. On one hand, controllable synthesis techniques for high‐quality materials are not yet mature; on the other hand, for a given material, the structure‐property relationship between its intrinsic electronic structure and saturable absorption characteristics should be systematically elucidated, enabling targeted optimization for specific applications. This study focuses on a ternary low‐dimensional material, ZrGeTe 4 , and develops an optimized liquid‐phase exfoliation process, enabling the controllable preparation of monolayer ZrGeTe 4 nanosheets with good repeatability. The correlation between the band structure and saturable absorption characteristics of monolayer ZrGeTe 4 was systematically investigated by both theoretical and experimental approaches. A monolayer ZrGeTe 4 saturable absorber was employed in a 1 µm all‐solid‐state laser, enabling Q‐switching and mode‐locking operations. The shortest Q‐switched pulse duration and mode‐locked pulse width were 35.25 ns and 716 ps, respectively. These findings may provide key insights for the applications of ternary chalcogenide materials ZrGeTe 4 in optoelectronics and ultrafast photonics.