Laser Modeling

3 Gain Saturation

This chapter presents the important concept of gain saturation, perhaps the second most important basic laser concept behind the development of the threshold gain equation. Gain saturation and the mathematical description of it are key to a number of models that follow in this text.

Presented in this chapter is one of the most important models in the text, a numerical “pass-by-pass” model that demonstrates how power in a laser grows. This model, based entirely on algebra and most conveniently implemented using a spreadsheet, allows a variety of laser parameters to be predicted as well as the implementation of “what if?” scenarios. The model is flexible and may be adapted to almost any laser, and while analytic solutions that ...