Fiber-optic array splicing with etched silicon chips

The two-dimensional array splicing concept using aluminum chips was reported earlier as a technique that is potentially suitable for field-splicing an optical cable containing linear arrays of optical fibers. Two arrays are stacked, epoxied, polished, and positioned to form a butt-joint splice. This paper reports the use of preferentially etched silicon chips to fabricate higher precision arrays which deviate from perfect uniformity by only 2.5 μm (0.0001 inch) on the average. Average losses for splices assembled with these arrays have been in the range 0.16 dB to 0.32 dB with a yield of 98.8 percent. These average losses are close to the anticipated values based on the measured mean offset between corresponding fiber axes in the spliced arrays. After several combinations of arrays were assembled and loss measurements made, the original array configuration was measured to test for array deterioration, loss measurement repeatability and final alignment repeatability. Only one fiber position showed evidence of contamination, and the mean splice loss was repeatable to within 0.02 dB.