Figure 13

Spectra of transmission coefficient of a silicon substrate (a commercial wafer, ρ =12 Ω cm), measured at two temperatures using two different BWO working in spectral ranges from 11 cm⁻¹ to 24 cm⁻¹ and from 29 cm⁻¹ to 39 cm⁻¹. Dots show the measurement results, lines are least-square fits based on the Drude conductivity model, as described in the text.