Optical fiber having first and second reflective surfaces and method of operation

#This invention relates to the field of optics and more particularly to an optical fiber having first and second reflective surfaces.

#Fiber optic communication systems include optical components, such as optical fibers, that transmit and receive optical signals. An optical signal propagating through an input optical fiber may exit the input optical fiber at a particular angle for communication to an output optical fiber. The various optical components of a system, such as the optical fibers, are generally positioned with respect to each other using V-grooves, or other similarly pre-fabricated alignment tools. A problem with prior fiber optic communication systems is that the pre-fabricated alignment tools may not be able to support the output optical fiber in a position appropriate for receiving the optical signal from the input optical fiber. One approach to solve this problem attempts to custom manufacture alignment tools to accommodate optical fibers that receive optical signals at various angles. This approach is costly, time consuming, and inefficient.

#An optical fiber having first and second reflective surfaces is provided that substantially eliminates or reduces disadvantages and problems associated with prior optical fibers.

#For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying figures in which like reference numbers indicate like features and wherein:

#FIG. 1 illustrates an optical fiber having a first reflective surface and a second reflective surface in accordance with the present invention; and

#FIGS. 2A-2D illustrate a method of forming an endface of an optical fiber in accordance with the present invention.

#FIG. 1 illustrates an optical fiber 10 that includes a core 12 designed to transmit or receive information in the form of light pulses, such as an optical signal 20, and a cladding 14 that surrounds core 12 to prevent signal 20 from escaping core 12 during transmission. Optical fiber 10 further comprises a first reflective surface 22 and a second reflective surface 26. In general, first reflective surface 22 totally internally reflects optical signal 20 at a first reflection angle and second reflective surface 26 totally internally reflects optical signal 20 at a selected second reflection angle.

#Core 12 of optical fiber 10 comprises any suitable refractive material, such as glass, having a particular index of refraction. Cladding 14 of optical fiber 10 comprises any suitable refractive material, such as glass, having an index of refraction lower than that of core 12 such that signal 20 propagates along the longitudinal axis 16 of optical fiber 10. Optical fiber 10 may comprise a multi-mode fiber having a large core (e.g., 50 or 62.5 microns wide) or a single mode fiber having a small core (e.g., 9 microns wide). Although the following description is detailed with reference to a fiber 10 having a circular cross section, it should be understood that the cross section of fiber 10 may have any suitable shape. Optical signal 20 comprises visible light, infrared radiation, ultraviolet radiation, or any other suitable optical beam.

#First reflective surface 22 is formed at a first bias angle 24 measured counterclockwise with respect to a plane 30 that is normal to the longitudinal axis 16 of fiber 10. First reflective surface 22 forms an interface between optical fiber 10 and a refractive material 32. Refractive material 32 comprises air or any other suitable substance that has an index of refraction lower than that of core 12 of optical fiber 10. In general, optical signal 20 contacts first reflective surface 22 of fiber 10 at an incident angle 38 measured clockwise with respect to a vector 40 that is normal to reflective surface 22. Accordingly, if the incident angle 38 of signal 20 is equal to or above a critical angle of refraction associated with the interface between core 12 of fiber 10 and refractive material 32, then first reflective surface 22 totally internally reflects optical signal 20 at a first reflection angle 34 measured clockwise with respect to longitudinal axis 16. First reflective surface 22 of fiber 10 therefore reflects optical signal 20 by total internal reflection (TIR).