Hybrid integration of two-dimensional dichalcogenides for low-power saturable absorption in photonic integrated circuits

Silicon photonics provides a versatile platform for large-scale integration of optical functions, but its weak intrinsic nonlinear response limits the realization of active, intensity-dependent functionalities. Hybrid integration of two-dimensional (2D) materials has emerged as a promising strategy to overcome these limitations by enabling strong light–matter interaction and broadband absorption. Here, we demonstrate saturable absorption in a complementary metal-oxide-semiconductor (CMOS), compatible silicon-on-insulator (SOI) microring resonator integrated with an exfoliated monolayer of 1T ′ -MoTe 2 . Transmission measurements under varying input powers reveal a clear nonlinear absorption response, with a saturation power as low as 2±1µW. A phenomenological model accurately reproduces the experimental results, confirming the nonlinear behavior induced by the hybrid MoTe 2 integration. These findings establish a proof-of-concept for ultracompact, low-power saturable absorbers in photonic integrated circuits (PICs), paving the way for applications in integrated lasers, ultrafast optical signal processing, and neuromorphic photonics.