1. At the end of Section 21.14 it was noted that the intensity of light absorbed while passing through a 16-kilometer length of optical fiber glass is equivalent to the light intensity ab- sorbed through for a 25-mm thickness of or- dinary window glass. Calculate the absorption coefficient b of the optical fiber glass if the value of b for the window glass is 10-4 mm-1.
Atomic and Electronic Interactions
2. Gallium arsenide (GaAs) and gallium phosphide (GaP) are compound semicon- ductors that have room-temperature band gap energies of 1.42 and 2.25 eV, respec- tively, and form solid solutions in all pro- portions. Furthermore, the band gap of the alloy increases approximately linearly with
GaP additions (in mol%). Alloys of these two materials are used for light-emitting diodes wherein light is generated by con- duction band-to-valence band electron transitions. Determine the composition of a GaAs-GaP alloy that will emit red light having a wavelength of 0.68 mm.