Applications of Hyperbolic Metamaterial Substrates

Figure 8

Subsurface sensing: illumination of a Si wafer from below by 𝜆∼9.8 μm. The incident light scatters through cracks in the wafer. (a) A subwavelength dimension crack in a Si wafer can be detected by a near-field scanning optical microscope (NSOM) only if the detector is brought very close to the crack (<𝜆/6). (b) If an AlInAs/InGaAs HMM is placed above the wafer, then the NSOM can detect the crack up to 2-3×𝜆 from the wafer. The HMM allows high spatial frequencies to propagate and enhances their intensity in the image.

(a)

(b)