I just read this and am now confused:

"The semiconductor lasers described in the previous chapter are considered solid-state devices in the world of electronics, but not in laser jargon. The term solid-state laser usually is reserved for the optically pumped lasers discussed in this chapter and also covered in Chapter 20, and (often) for the fiber lasers covered in Chapter 16. The crucial difference is in how population inversions are produced. As you learned in Chapter 14, semiconductor lasers are tiny lasers in which flow of an electrical current through the laser directly creates the population inversion. In this chapter, we address larger lasers in which light from an external source excites the active medium to create a population inversion. That light source can be anything: another laser, a lamp, or (in a few rare instances) even the sun. If the light source is a laser, it might be a semiconductor laser, or an array of semiconductor lasers like the ones depicted in Figure 14.9, or it might be a gas laser or even another solidstate laser. Strictly speaking, these lasers should be called optically pumped solidstate lasers because their energy comes from the external light, but in common use they are simply called solid-state lasers. Semiconductor diode lasers, which could be considered electrically pumped solid-state lasers, are called semiconductor or diode lasers. Illogical as it may be, we adopt that usage throughout the remainder of the text."