In a fiber-optic link, this can be caused by improper alignment of connectors or splices. A cavity with mirrors at opposite ends. It is a foundation component of certain lasers and passive filters.

Fusion splicing is the process in which fiber optic cables are connected by heat, a process often used in data centers. Instructors say the need for fiber optic technicians has increased due to ...

and explains the design decisions he’s made — from splicing fiber optics himself, to building a PC to do routing instead of getting a hardware Small Form-factor Pluggable (SFP) equipped router.