1：Experimental Design and Method Selection:

The study uses a back focal plane microscopy setup combined with a solid immersion lens for direct imaging of isofrequency contours. Numerical simulations are performed using the Fourier modal method and FDTD simulations to model re?ectivity and ?eld distributions.

2：Sample Selection and Data Sources:

The metasurface sample is fabricated on a silicon on insulator substrate using e-beam lithography and reactive ion etching, with parameters p=180 nm, d=125 nm, h=70 nm. Data is acquired from experimental measurements and simulations.

3：List of Experimental Equipment and Materials:

Supercontinuum laser source (Fianium WhiteLase SC400-6), acousto-optic ?lter (Fianium AOTF), high-NA objective (Mitutoyo M Plan Apo HR, 100x,

4：9 NA), ZnSe solid immersion lens, piezo positioner, CMOS camera. Materials include crystalline silicon, silica buffer layer. Experimental Procedures and Operational Workflow:

Linearly polarized light is focused on the SIL surface, with the gap controlled by a piezo positioner. Re?ectivity dips are imaged in the back focal plane using a lens system and CMOS camera. Simulations involve FMM for re?ectivity maps and FDTD for ?eld distributions from dipole excitations.

5：Data Analysis Methods:

Data is analyzed to reconstruct dispersion relations ω(kx, ky) by combining isofrequency curves from multiple wavelengths, with comparisons to numerical simulations.