The drive to faster data transmission speeds, more integration, smaller form factors and higher signal integrity all favor the eventual adoption of optical transmission schemes in data buses. This contribution will discuss emerging technologies from Shipley Company, LLC to address the needs of optoelectronic signal transmission. In particular, the discussion will focus on materials and processes that are in development to function within existing printed circuit board (PCB) & microelectronic manufacturing schemes. One topic that is described in detail involves photo-patternable, polymer interconnect technologies. Another topic describes progress in Shipley’s ability to integrate these interconnects into prototypical PCB processes. Progress in connecting the planar waveguides to connectorization schemes will be also be described. Other topics include lithographic and patterning metrics, optical characteristics of interconnects, morphological features of patterned waveguides, integration and coupling considerations, thermal and mechanical properties of the system and general assembly processes..

Recent developments and applications of polymer waveguides will be reviewed in the areas of devices, packaging and high speed board interconnects.

Life extension programs for military metallic aircraft are becoming increasingly important as defense budgets shrink and world economies realign themselves to an uncertain future. For existing military weapon systems, metallic corrosion damage costs an estimated $8 billion per year. One approach to reducing this cost is to develop a reliable method to detect and monitor corrosion in hidden metallic structure with the use of corrosion sensors which would give an early indication of corrosion without significant disassembly, thereby reducing maintenance costs. This presentation describes the development, analysis, and testing of a fiber optic corrosion sensor developed jointly with the Virginia Polytechnic Fiber gr Electro-Optics Research Center and sponsored by Wright Laboratory Materials Directorate, contract #F33615-93-C-5368. In the sensor which was researched under this contract, the normal cladding is removed in the sensor region, and replaced with aluminum alloy and allowed to corrode on coupons representative of C/KC-135 body structure in an ASTM B117 salt spray chamber and a Boeing developed Crevice Corrosion Cell. In this approach, the optical signal output of the sensor was originally designed to increase as corrosion takes place, however interaction with the corrosion byproducts yielded different results than anticipated. These test results to determine a correlation between the sensor output and the structural degradation due to corrosion are discussed.

Life extension programs for military metallic aircraft are becoming increasingly important as defense budgets shrink and world economies realign themselves to an uncertain future. For existing military weapon systems, metallic corrosion damage costs an estimated $8 billion per year. One approach to reducing this cost is to develop a reliable method to detect and monitor corrosion in hidden metallic structure with the use of corrosion sensors which would give an early indication of corrosion without significant disassembly. This paper describes the current status of the development, analysis, and testing of a fiber optic corrosion sensor developed jointly by Boeing and Virginia Tech Fiber & Electro-Optics Research Center and sponsored by USAF Wright Laboratory, Materials Directorate, contract #F33615-93-C-5368. In the sensor which is being developed under this contract, the normal cladding is removed in the sensor region, and replaced with aluminum alloy and allowed to corrode on coupons representative of C/KC-135 body structure in an ASTM B117 salt spray chamber. In this approach, the optical signal out of the sensor is designed to increase as corrosion takes place. These test results to determine the correlation between sensor output and structural degradation due to corrosion are discussed.

A non-contact optical method has been developed for the remote and high-speed interrogation of optical fiber sensors embedded in a structure. The technique allows the use of passive fiber sensor requiring no local on-board electrical power or local electronics in the structure, thus simplifying the design and manufacturing of the structure, and allowing potential applications in low-cost structures where the addition of on-board power and electronics may be cost- prohibitive. For demonstration, multiple absolute extrinsic Fabry-Perot interferometric (AEFPI) strain sensor elements were embedded in a polymer matrix cross-ply laminate coupon. Coupling of broadband optical power into the embedded sensor elements over a distance of several tens of centimeters was achieved using a compact and lightweight broadband light source. Optical radiation received back from the sensors within the test specimen was optically detected and electronically processed to obtain the AEFPI strain sensor output signals using a computer software-based signal processing unit designed for this application. The ability of the opto-electronic receiver unit to both detect changes in strain dynamically was determined by quasi-satirically increasing the load on the specimen using a small loading fixture. The further ability of the system to monitor strain dynamically during rapid motion was demonstrated by moving the specimen with respect to the input and output optics. The limitations of the system due to the operation of the detection system are detailed.

Optical fiber grating-based sensors are proposed and demonstrated for the detection of corrosion. Two techniques are employed to indirectly monitor corrosion: (1) measuring the corrosion-induced decrease in the residual strain of a metal-coated optical fiber short period grating sensor and (2) monitoring corrosion-induced changes in the dimension of a metal- coated, long-period grating sensor.