High fiber count optical penetrator: Evaluation of thermally induced stresses

In the past thirty years, the need for increased power and optical fiber counts in undersea systems has been rather dramatic. Most cable designs are readily adaptable to increased counts of optical fiber, whereas interconnects and pressure vessel designs are significantly more complex. In some cases, optical fiber counts in undersea systems are limited by the feedthrough and/or interconnect configurations. General Dynamics Mission Systems has addressed this constraint and now provides a family of high reliability electro-optical feed through penetrators. Within this family of penetrators, is a high reliability optical penetrator capable of sealing in bulkhead and in-line configurations. Recent development efforts have produced a 24-fiber penetrator configuration, which incorporates two twelve fiber ribbons, thus greatly enhancing the manufacturability and handling characteristics. In support of the design verification testing, analysis and testing of the fiber strain during fabrication and service conditions has been completed and compared to the qualified baseline configuration (≤ 8 fibers per unit). The testing validates the analytical predictions of low strain and correlates well to prior work, thereby indicating 24 fiber penetrators will provide the same high reliability performance as their 8 fiber predecessors. This paper documents the recent developments, testing and analysis for a 24 fiber high reliability optical fiber penetrator.