Polymer claddings with low refractive indices for silica core fibers were developed. Applications include fiber
lasers and transmission of high power lasers in surgery. For many applications, operating fibers under high
temperatures is desirable. In a previous publication, the results of testing polymer cladded silica core fiber at 150°C
for 6400 hours were given, along with 5000 hours of testing polymer films. The results at 150°C were encouraging,
with little additional loss measured. Here we test polymers under more severe conditions, at 270°C, for periods up
to 10 hours. The polymers' cured indices range from 1.374 to 1.397 (at 852 nm). Changes in Young's modulus,
refractive index, yellowing, weight, hardness, strength, and elongation were observed. While these polymers cannot
function at 270°C for extended periods, it is possible to expose them for shorter durations without significant
damage. Some polymer properties actually improved after 4 hours of heating. Fibers clad with such polymers have
been successfully jacketed with extruded materials, and have endured high temperatures for a few minutes. It is
possible that a sensor, fiber laser or other fiber device could function in these temperatures for short periods without
the coating properties changing beyond values required for operation.
Low index polymer claddings were developed and tested for use with silica core fibers. Polymers with varying indices of
refraction were developed, so that numerical apertures useful for multiple applications were produced. High transmission
over a wide wavelength range was obtained, both for films and for clad fibers. A refractive index as low as 1.363 was
achieved, which results in a numerical aperture of 0.50 (at 852 nm) when used in cladding silica cores. Results for fibers
clad with 1.373 index material under high temperatures (150 °C) show that worst case change in loss was within 0.084
dB, even over a time frame of 6400 hours.
We studied optical materials with lower refractive indices than silica, which can be used in fiber optic technology applied to medical devices. The materials were tested for biocompatibility. This paper details the experiment based on USP biocompatibility specifications, its results, and the optical properties of this material.
Demodulation of internal fiber Bragg grating sensors has been demonstrated. Methods are described by which remote fiber gratings can be interrogated, in order that the direction and magnitude of environmentally induced changes, such as temperature or strain, might be measured.
McDonnell Douglas has been developing fiber optic communication links and data bases for aerospace applications since 1975. These efforts have been complemented by a strong program in fiber optic sensor development that began in 1977. This paper provides an overview of some of the highlights of these efforts and a partial listing of McDonnell Douglas publications and patents in the area.
The present examination of the use of fiber-optic (FO) networks in launch vehicles proceeded from the definition of a data bus architecture able to supplant the mesh network that typically connects major second-stage avionics packages, as well as replacing the takeoff-minus-zero umbilical link between vehicle and launch complex. The analysis undertaken for such a system in the case of a Delta launcher gave attention to bus traffic, costs, and risk factors; on the basis of analysis results, a hybrid FO/electrical network was selected and its candidate termini were tested for ruggedness and reliability.