In my earlier articles, I have explained the construction of semiconductor laser. Toady I will discuss the working of semiconductor laser.
Achievement of population inversion: When p-n junction diode is forward biased, then there will be injection of electrons into the conduction band along n-side and production of more holes in valence band along p-side of the junction. Thus, there will be more number of electrons in conduction band comparable to valence band, so population inversion is achieved.
Figure: Energy level diagram of semiconductor laser (No biasing)
Figure: Energy level diagram of semiconductor laser (with biasing) Continue reading “Working of semiconductor laser”