- B In The Figure Below The Real And Imaginary Parts Of The Dielectric Constant Of An Optical Material Are Graphed Est 1 (162.32 KiB) Viewed 27 times
(b) In the figure below, the real and imaginary parts of the dielectric constant of an optical material are graphed. Estimate the wavelength at which &z = 0 and the value of Ez at this wavelength. What are the corresponding values of the real and imaginary parts of the refractive index? -Re() - Im(e) 3 2 1 (V) 0 -1 -2 3 600 800 1000 1200 1400 1600 Wavelength (nm) [4 marks] (e) An optical sample consists of two sections of length and l, with surface reflectivity of R, and R. and having extinction coefficients K and Kz is shown in the diagram below. For light of incident wavelength 1, and incident intensity I., derive an expression for the optical transmission through this sample. [6 marks) (Determine the value of optical transmission for the sample in part (e) above where the wavelength of the incident light and the values for real and imaginary parts of the refractive index for material 1 are as estimated in part (b) above and material 1 has a thickness of 100 nm. Material 2 has values of n2 = 1.3 and K2 = 0.5 with a thickness of 150 nm and the intensity of the incident light lo= 1.0 Wm [5 marks) Note: the Fresnel Reflectivity Rfor normal incidence of light is given by: (n-1)2 + x2 R= (n + 1)2 + x2