A fiber taper, or tapering, refers to the reduction object size in the shape of cone or conical, like sharp pencil tip. Tapering in the casual description of a shape or object, a gradual thinning or narrowing towards one end (i.e., a conical tapered profile).
Multi mode or single mode optical fibers can be produced by gently stretching at the one end of the fiber while it is heated or over flame. In the photonics industry end tapers are many times used for the purpose of mode matching by reducing mode area as conically tapered and it would increase the numerical aperture (NA) by changing the acceptance angle and it increases the coupling efficiency of the source. End tapers are helpful to improve waveguide coupling and mode matching too.
