Acoustic Fiber Waveguide Coupler

A fused biconical taper acoustic fiber waveguide couuler for application in acoustic fiber sensing systems has been developed and evaludted. The coupler is fabricated by twisting together two glass-on-glass acoustic fiber waveguides and fusing them using applied heat. Fulling on the fibers minimizes the coupler's taper region. The subsequent pushing together of the fibers forms a glass ball at the center of the coupler region. The heated fibers are then pulled again until the desired acoustic coupling S-parameters are achieved. This new method of acoustic fiber coupler fabrication allows coupler performance evaluation based upon taper symmetry, fiber geometry and measurement tolerance. Fiber coupler operation and measurements cf coupler performance are presented.