A single-quantum well of GaAs with a thickness of 60 A is incorporated into ˚ a GaAlAs heterojunction laser. The laser has a stripe geometry, being 200 μm long and 10 μm wide. (a) What is the emission...

A single-quantum well of GaAs with a thickness of 60 A is incorporated into ˚

a GaAlAs heterojunction laser. The laser has a stripe geometry, being 200 μm

long and 10 μm wide.

(a) What is the emission wavelength if the energy bandgap is Eg = 1.52 eV

in the emitting region and electron transitions occur between the n = 1

level in the conduction band and the n = 1 level in the valence band?

(b) If the gain coefficient of the laser in part (a) is g = 80 cm−1, what would

be the gain coefficient of a multiple quantum well laser with 20 identical

wells?