Double eccentric connectors for optical fibers

An optical fiber connector with an adjusting mechanism using double eccentric tubes is reported. Tolerable impairment values of possible factors affecting connection loss are evaluated. The main factors of the connection loss are mutual core displacement and fiber axis tilt. By using a double eccentric adjusting mechanism, a 0.57-dB average connecting loss between step index multimode fibers is obtained without matching material. The connection loss can be attributed quantitatively to several impairment factors. Using a transparent thin film in the connecting section, the reflection can be reduced as low as about -25 dB, and the average connecting loss was improved to about 0.20 dB.