The equivalent refractive index , equivalent relative impedance , and are derived from reflection and transmission coefficients measured from both sides of the air/SWF/substrate system using a method described elsewhere.12 The equivalent relative impedances and are associated with forward (+) and backward (−) directions of light propagating through the air/SWF/BK7 glass system (Fig. 1). The equivalent relative permittivity , equivalent relative permeability , and bianisotropic parameter are then calculated from , , and , respectively. Additionally, the complex-valued reflection coefficients and transmission coefficients of the SWF are measured for the SWF deposited on the glass slide, by using a walk-off interferometer with a wavelength-tunable 35 KAP 431-220 Ion Laser System (CVI MellesGriot, Albuquerque). The measurements are also taken at three wavelengths: 476, 568, and 676 nm. Figure 3 plots the values of at the three wavelengths and Table 2 lists the values and . Figure 4 presents the equivalent electromagnetic parameters and optical parameters of the three samples. The magnitude of the real part of the refractive index increases with wavelength, subsequently preventing the optical thickness varying intensively with wavelength. The imaginary part of the refractive index is sufficiently low to have interference between the first two reflected waves from SWF. The value is within the range (0.117, 0.137) for SWF-A, (0.046, 0.073) for SWF-B, and (0.086, 0.098) for SWF-C. As the thickness of SWF increases from 420 to 480 nm, the equivalent refractive index is negative; in addition, its average magnitude decreases from to at a wavelength of 676 nm. Similarly, the real part of the equivalent permittivity varies from to as the thickness increases. Both equivalent permittivity and permeability are negative real, and the magnitude of the real part of the permeability increases as wavelength increases.