Polarization-Preserving Single Mode Fiber Coupler.
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
The present invention relates generally to fiber optical couplers, and more particularly to the fabrication of polarization-preserving fiber optical couplers. Optical-fiber-to-fiber couplers for coupling an optical beam from one or more fibers to another fiber or fibers are known in the art. A polarization-preserving single mode fiber coupler is fabricated by a method which does not require mutually aligning the fiber polarization axes provided the actual misalignment angle is is not close to 90 degs. The protective jackets from two or more polarization-preserving single mode birefringement fibers are partially removed and the fibers are twisted around each other to bring them into contact over the jacketless region and provide a coupling length that is large compared to the birefringent beat length of the fibers. Next, the cladding layers of the fibers in the contacting region are partially etched without degrading the birefringent beat length over their coupling length. Then, the etched region is heated to the softening point of the fibers while axial tension is applied to taper and fuse the etched region until a desired coupling of the fibers is achieved. Finally, a mechanical supporting structure is added to the tapered and fused region of the fibers.
- Electrical and Electronic Equipment
- Fiber Optics and Integrated Optics