Submicron alignment of a two-dimensional array of multiple single-mode fibers

This letter presents a patented method to align single- or multimode optical fibers on top of an optoelectronic emitter array. Electrostatic forces are used to align copper-coated optical fibers within adhesive filled holes. The manufacturing and alignment performance of a microholder with a hole diameter of 1000 μm are fully characterized. The outer diameter of the optical single-mode fiber is 125 μm including the cladding. A submicron alignment accuracy can be inferred from the measurements taken. The sensitivity of the alignment procedure has been found to be between 0.25 and 1 μm per volt depending on the clamping distance. The combination of the electrostatic movement and the optical monitoring of the fiber position in a closed-loop feedback system yield a highly accurate and sensitive active alignment system.