An optical switch for the SL undersea lightwave system

A 4 × 1 mechanical optical switch has been constructed, which can be used to switch the laser source in regenerators of the SL Undersea Lightwave System. We describe the design philosophy used to meet the high reliability required of < 2 FIT's as a passive component, and
< 10^{-3}
probability of not performing the switch-over function when called upon in 25 years. We describe the grooved silicon chips which were especially designed for this application for the precise alignment of the optical fibers. We also describe a novel fiber end seal. Included are recent loss results for both a 4 × 1 and a 2 × 1 mechanical optical switch.