ABSTRACT
Passive optical alignment is the method for aligning optical elements, including lasers, optical semiconductor devices, or lenses, without having to power the system to find the positions. If the system is powered to find the alignment, then the alignment is called an active alignment. Active alignment is commonplace but can be expensive to use. The term passive alignment usually applies to tiny optical elements ordinarily found in fiber optic components and systems, planar lightwave circuits (PLCs), or free-space micro-optical systems. In recent years passive alignment has gained importance in reducing the manufacturing cost of fiber optic components, in particular, and in enabling the assembly of more complex optical systems that do not easily lend themselves to active optical alignment. Probably the oldest and simplest form of passive optical alignment is the alignment that takes place when snapping together an optical cable connection. Chapter 2 will discuss this type of passive alignment in detail.
