Fiber optic cable assembly having a connector with a holographic optical element and method of making same
View Patent ↗A method of making a fiber optic cable assembly having a fiber optic cable terminated by at least one connector is disclosed. The at least one connector includes a ferrule with a holographic optical element and the fiber optic cable includes at least one optical fiber. The method includes securing the at least one optical fiber to the ferrule and exposing the holographic optical element to light from the at least one optical fiber to write an interference pattern into the holographic optical element corresponding to the at least one optical fiber. A fiber optic cable assembly made according to the method is disclosed and an apparatus for carrying out the method is also disclosed.
1. A method of making a fiber optic cable assembly that includes a fiber optic cable and at least one connector, the at least one connector having a ferrule with a holographic optical element, and the fiber optic cable having a plurality of optical fibers, the method comprising:
securing the plurality of optical fibers to the ferrule to fix relative positions of ends of the plurality of optical fibers and the holographic optical element, wherein the ends of the plurality of optical fibers arranged in a fiber array; and
with the plurality of optical fibers secured to the ferrule, exposing the holographic optical element to light from the plurality of optical fibers to write an array of interference patterns into the holographic optical element corresponding to the fiber array, wherein exposing further comprises:
energizing a laser to generate a laser beam;
splitting the laser beam into an object beam and a reference beam;
directing the object beam into the plurality of optical fibers of the fiber optic cable such that the light from the ends of the plurality of optical fibers projects onto a first surface of the holographic optical element; and
directing the reference beam to project onto a second surface of the holographic optical element,
wherein the interaction between the object beam and the reference beam at the holographic optical element creates the array of interference patterns corresponding to the fiber array.
2. The method of claim 1 , wherein securing the plurality of optical fibers to the ferrule further comprises:
inserting each of the plurality of optical fibers into a respective micro-bore in the ferrule;
positioning each of the ends of the plurality of optical fibers along a common plane; and
securing each of the plurality of optical fibers to the ferrule after said positioning.
3. The method of claim 2 , wherein the ferrule includes an end wall section formed from a material that has substantially the same refractive index as cores of the plurality of optical fibers, the method further comprising:
engaging the end of each of the plurality of optical fibers against a first surface of the end wall section to define the common plane; and
engaging the holographic optical element against a second surface of the end wall section that is spaced from and opposite to the first surface.
4. The method of claim 2 , wherein the plurality of micro-bores in the ferrule are arranged in a two-dimensional pattern.
5. The method of claim 4 , wherein the plurality of micro-bores is arranged in a rectangular pattern having between 2 and 8 rows and between 6 and 36 columns.
6. The method of claim 1 , further comprising directing the object beam into a beam splitter such that each of the plurality of optical fibers carries the object beam.
7. The method of claim 1 , further comprising:
removing the holographic optical element from the ferrule;
developing the holographic optical element; and
reconnecting the holographic optical element to the ferrule.
8. The method of claim 1 , wherein the connector further includes a housing, the method further comprising positioning the ferrule within the housing of the connector.