Semiconductor Laser Operation

Abstract

In the previous chapter, we talked about the ideal properties of semiconductors and semiconductor quantum wells, including density of states, population statistics, and optical gain, and develop expressions for these that are based on ideal models. In this chapter, we will take a step back to see how optical gain and current injection interacts with the cavity and photon density to realize lasing. Finally, we present a simple rate equation model and examine it to see how laser properties such as threshold and slope are predicted. The predictions from the rate equation model are related to the measurements which can be made on these devices to determine fundamental properties of laser material and structure, including internal quantum efficiency and transparency current.

…

Rail on in utter ignorance

Of what each other mean,

And prate about an Elephant

Not one of them has seen!

—John Godfrey Saxe

The Blind Men and the Elephant