The \"FP\" stands for Fabry-Perot. Fabry-Perot laser diode has very simple structure: two reflective mirrors and an active section between the mirrors. Most laser systems can be simplified as FP oscillators. FP laser diode is made by cleaving the facets of a semiconductor PN junction. The facets are naturally reflective because of the difference on refractive index of the semiconductor material and the air. Different high reflective and wav..