1. Zinc selenide has a band gap of 2.58 eV. Over what range of wavelengths of visible light is it transparent?
2. Briefly explain why the magnitude of the ab- sorption coefficient (b in Equation 21.18) depends on the radiation wavelength.
3. The fraction of nonreflected radiation that is transmitted through a 5-mm thickness of a transparent material is 0.95. If the thickness is increased to 12 mm, what fraction of light will be transmitted?
Transmission
4. Derive Equation 21.19, starting from other expressions given in the chapter.
5. The transmissivity T of a transparent mate- rial 15 mm thick to normally incident light is 0.80. If the index of refraction of this mate- rial is 1.5, compute the thickness of material that will yield a transmissivity of 0.70. All reflection losses should be considered.