
Optical feedback in lasers
Theoretical knowledgeThe general function of lasers is based on optical feedback. Photons emitted from the active region are back-reflected by the mirrors into the gain medium. In this way, optical feedback is realized and finally controls the process of stimulated emission. But when speaking of optical feedback one usually refers to external optical feedback. Here is a review of optical feedback effects and consequences on a laser spectrum. Optical feedback is often associated to an undesirable optical feedback in the optical…