Fig. 3: Experimental characterization of the band gap of Yukawa-potential amorphous structures and corresponding waveguides.

a Transmission spectra of straight waveguides embedded in an amorphous structure with w = 901 nm and r = 100 nm. The dashed lines indicate the transmission spectra through a section of amorphous structure, whereas the distance from the excitation source is indicated in the legends. b Scanning electron microscopy (SEM) of an optical waveguide based on a YPAS with T^* = 0.2 and r = 120 nm. The waveguide is oriented along the x-axis and has a width of 901 nm. Scale bar: 5 μm. Insets show zoom-in SEMs of different regions of the waveguide. Scale bars: 500 nm. c Measured (blue and black lines) and fitted (red line) transmission spectra of the amorphous waveguide structure oriented along x-axis (blue) and y-axis (black). The 3 dB cutoff wavelength is ~ 1448 nm. d The same as in b, except that the waveguide is oriented at an angle of 23 ^∘ with respect to the x-axis. e The same as in c, but for the waveguide in d. The 3 dB cutoff wavelength is ~1478 nm.