Fig. 1. Schematic of the PtSe₂-on-silicon nitride MRR. (a) Three-dimensional view of the device; (b) top view of the device; (c) cross-sectional view of the waveguide.

Fig. 2. Characterization of the five-layer PtSe₂ on the surface of the silicon nitride chip. (a) The AFM characterization of the PtSe₂ film; (b) the Raman spectrum of the PtSe₂ film measured using a Raman spectrometer with a pump wavelength of 785 nm; (c) the measurement result of the XPS full spectrum; the Gaussian fitting curves of (d) Se 3d peak and (e) Pt 4f peak in (c).

Fig. 3. Characterization of the PtSe₂-on-silicon nitride MRRs. (a) and (d) the SEM images of two MRRs with the PtSe₂ film coverage, with estimated lengths of the material covered of 125 and 471 µm. (b) and (c) The transmission spectra of the MRR in (a) before and after the PtSe₂ film transfer; (e) and (f) the transmission spectra of the MRR in (d) before and after the PtSe₂ film transfer.

Fig. 4. Optical nonlinearity measurement and simulation results. (a) Schematic of the experimental setup; (b) measured transmission spectra at different input power levels; (c) resonant wavelengths at different input powers; (d) simulated transmission spectra at different input powers using the time-domain CMT method; (e) simulated resonant wavelengths at different input powers; (f)–(h) hysteresis loop simulations for the input wavelengths of 1541.55, 1541.56, and 1541.57 nm; arrows in (f)–(h) indicate the directions of the input power variations.

Fig. 5. Electromagnetic thermal simulation results of the waveguide cross section. Temperature distributions of (a) the PtSe₂-on-silicon nitride waveguide cross section and (b) the bare waveguide cross section.

Table 1. Parameters and Sources Used in CMT Simulation