An assembly for improved alignment of a laser for generating laser light with an optical fiber having an end section terminating in a light-receiving end. A laser housing has a base and substantially cylindrical housing walls mounted at a bottom portion to the base. The laser can be mounted on the base. The substantially cylindrical internal surface of the cylindrical housing walls have internal threads at a top portion. The internal threads have a minor diameter and a major diameter. An annular ferrule housing has a substantially cylindrical through-hole with an inner diameter sufficient to receive a fiber ferrule which has the end section of the fiber disposed therein. The ferrule housing further has an axially tapered external surface having external threads which are threadably compatible with the internal threads. The major diameter of the external threads decreases monotonically from a first major diameter at a top portion of the external surface to a comparatively smaller second major diameter at a bottom portion of the external surface. The first major diameter of the external threads is larger, and the second major diameter of the external threads is smaller, than the minor diameter of the internal threads.