Collimator array
View Patent ↗A collimator array using a molded element to hold the input fibers and to collimate the light. The input fibers are held within holes in one face of the element, and the collimation of the light emitted from the ends of the fibers is performed by an array of lenses appropriately located such that each lens collimates the light emitted from a fiber end. The lateral spacing between the holes is made to be equal to the lateral spacing between the lenses of the array. Since, in a molded element, this lateral spacing can be accurately provided, good alignment of the input fibers with the lenses can be achieved. The depths of the holes can be made such that when a fiber is inserted right to the bottom of a hole, the end of that fiber is accurately located such that the light emitted therefrom is collimated by the lens. This avoids the need for accurate manual alignment of the fibers of the array. Alternatively, the hole can be made slightly deeper than this predetermined depth, to provide some adjustment in the lens-fiber distance for adjusting the level of collimation.
1. A collimator array comprising:
an integral, monolithic block of a transparent optical medium, said block comprising:
an array of holes formed in said block and adapted to receive the ends of an array of optical fibers; and
an array of lenses formed in said block and adapted to collimate light emitted from the ends of optical fibers inserted into said holes, and impinging on said lenses;
wherein said array of holes and said array of lenses are located such that the lateral spacing between adjacent ones of said lenses is the same as the lateral spacing between adjacent ones of said holes, and successive ones of said array of lenses are aligned to receive light emitted from fibers inserted into successive ones of said array of holes.
2. A collimator array according to claim 1 and wherein said array of holes is formed in a first surface of said block, and said array of lenses is formed in a second surface of said block, said first surface being disposed opposite said second surface, such that light from ends of said optical fibers is transmitted directly to said lenses.
3. A collimator array according to claim 1 and wherein said array of holes are formed in a first surface of said block, and said array of lenses is formed in a second surface of said block, said first surface being disposed at an angle to said second surface, and wherein said block also comprises a third reflective surface disposed such that light from ends of said optical fibers is transmitted by reflection in said third surface to said lenses.
4. A collimator array according to claim 1 and wherein said array of holes and said array of lenses are formed in a first surface of said block, and wherein said block also comprises a second reflective surface disposed opposite said first surface, said holes being disposed at an angle such that such that light from ends of said optical fibers is transmitted by reflection in said second surface to said lenses.
5. A collimator array according to claim 1 , and wherein the depths of said holes are arranged such that the optical distance between the end of a hole and the lens associated therewith is such that when a fiber is inserted to the end of said hole, said lens associated with said hole collimates light emitted from the end of said fiber and falling on said lens.
6. A collimator array according to claim 5 and wherein said optical distance between the end of said hole and the lens associated therewith is equal to the focal length of said lens.
7. A collimator array according to claim 1 , and wherein the depths of said holes are arranged such that the optical distance between the end of a hole and the lens associated therewith is less than the focal length of said lens, such that the longitudinal position of the end of said fiber within said hole can be adjusted to adjust the collimation provided.
8. A collimator array according to claim 1 , and wherein said block is formed of a molding of said transparent optical medium.
9. A collimator array according to claim 8 , and wherein said transparent optical medium is either one of a moldable optical glass and a moldable optical plastic.