BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to optic fiber connectors, and more particularly, to receptacles for optical fiber stubs.

Description of Related Art

Optical fiber stubs are used in telecommunication systems and devices for systems such as for Transmit Optical Sub Assemblies (TOSAs) and Receiving Optical Sub Assemblies (ROSAs). A fiber stub has two ends, wherein one end includes an optical fiber mounted within a ferrule or connector interface. Normally the opposing end of an optical fiber stub has the fiber coupled directly or indirectly to an emitter or receiver electrooptic device, which is located within the optoelectronic module. The optical fiber includes both a core and a cladding. The optical fiber includes glass materials with several refractive indices, typically one with a higher numerical aperture that clads to another at the core of the fiber.

After an optical fiber stub is secured adjacent to a TOSA or ROSA within an electronic device using such optical devices, a receptacle cap typically is glued or welded to be permanently secured over the optical fiber stub. The receptacle cap includes an alignment sleeve for coupling and properly positioning an external optical ferrule containing an optical fiber adjacent to the optical fiber stub for efficient transmission of optical signals between the external optical ferrule and the optical fiber stub.

During assembly, testing, and interchanging external optical ferrules within the alignment sleeve of the receptacle cap, dirt or other impurities and occasional mechanical damage, can accumulate or occur on the outer end or end face of the optical fiber stub, thus negatively affecting the ability of the optical fiber to transmit or receive optical signals. Since the receptacle cap conventionally is permanently secured over the optical fiber stub, it can be very difficult to clean or re-polish to repair the outer end of the optical ferrule of the optical fiber stub. Since an electronic device utilizing optical fiber stubs can be expensive, reduced performance of an optical fiber stub due to contamination of the outer end of the optical ferrule of the optical ferrule stub that is permanently covered by a receptacle cap can have serious negative consequences.

Accordingly, there is a need for a design that enables the end face of an optical ferrule of an optical fiber stub covered by a receptacle cap to be easily accessible for cleaning, while maintaining proper alignment of an alignment sleeve within the receptacle cap relative to the optical fiber stub.

ASPECTS AND SUMMARY OF THE PRESENT INVENTION

One aspect of the present invention is to provide a removable receptacle cap for an optical fiber stub to enable the end face of the optical ferrule of the optical fiber stub to be easily cleaned or re-polished without damaging the optical fiber stub or the electronic apparatus to which the optical fiber stub is secured.

Another aspect of the present invention is to reduce manufacturing and repair costs.

In order to achieve these and other aspects, the present invention provides an optical fiber stub assembly, comprising a stub body having a first end and a second end, wherein an outer surface of the first end is threaded, and a stop surface is located at an end of the outer threaded surface of the first end. A receptacle cap having a tubular body with a base end and a receiving end, wherein an inner surface of the base end is similarly threaded to mate with the outer threaded surface of the first end, so that the base end of the receptacle cap can be screwed over and around the first end of the stub body. The receiving end of the receptacle cap includes two opposing flat surfaces on an outer surface, so as to enable a tool to grip the outer surface of the receiving end of the receptacle cap and unscrew the receptacle cap from the stub body. An alignment sleeve is located within the receptacle cap for receiving and properly positioning an optical ferrule relative to an end face of the optical ferrule of the stub body.

Another aspect of the present invention disclosed herein enables gases created during the sealing process of a hermetic-version of the stub, when the fiber stub is to be glass sealed at one end, to escape without damaging the hermeticity of the glass seal itself.

A further aspect of the present invention is to produce resilient hermetic seals in hermetic fiber stubs.

In order to achieve these and other aspects, another embodiment of the present invention provides a vent or slot between the ferrule and stub body that enables gases generated from the low melting glass sealing process of an optical fiber to the ferrule stub to escape, thus creating a stronger and more resilient and reliable seal between the optical fiber and low melting point glass and the stub body, creating the hermetic seal. Without such a vent, which is the conventional configuration, generated gases are forced into the molten glass during the sealing process, thus reducing the strength or resilience of the hermetic seal.

In accordance with a further embodiment of the present invention, an optical fiber stub is provided having a first end and a second end, and a base extending beyond an outer surface of the stub body. A receptacle cap or receptacle chimney having a tubular body with a locking end and a receiving end, wherein an inner surface of the locking end includes an internal rim or inner rim or recesses for receiving and securing a clip within. A polymer insulating insert having a first plurality of clips or annular clipping surfaces on a first side, and a second plurality of clips or annular clipping surfaces on the second side, wherein the first plurality of clips or annular clipping surface are configured to clip onto and secure the first side of the polymer insulating insert to the base of the stub body, and the second plurality of clips or annular clipping surface are configured to clip onto and secure the second side of the polymer insulating insert to the locking end of the receptacle cap. The polymer construction of the polymer insulating insert functions to provide electrical insulation between the optical fiber stub and the receptacle cap. Additionally, the color of the polymer insulating insert can be varied to indicate an optical signal input or an optical signal output.

The foregoing has outlined, rather broadly, the preferred features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed invention and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention, and that such other structures do not depart from the spirit and scope of the invention in its broadest form.

