MIL-PRF-49291 Fiber, Optical, \(Metric\) General Specification ForThis specification covers the general requirements and characteristics of optical fibers for signal transmission. The fiber is defined as the core, cladding, and protective coatings applied during the fiber drawing process.

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MIL-PRF-49291D

4.7.2.4 Mechanical strippability. The strip force of each individual fiber shall be measured in

accordance with TIA-455-178. Fibers shall be stripped of their coatings with the use of a commercially

available mechanical fiber stripper. After stripping, the fiber shall be inspected under 10X magnification

for compliance (see 3.5.3).

4.7.2.5 Materials tests for space applications.

4.7.2.5.1 Thermal vacuum outgassing. Non-metallic materials shall meet the requirements of 3.4.2.1

when tested in accordance with ASTM-E-595.

4.7.2.5.2 Odor. Material samples shall meet the requirements of 3.4.2.2 when tested in accordance

4.7.2.5.3 Toxicity. Material samples shall meet the requirements of 3.4.2.3 when tested in accordance

4.7.3 Optical inspections.

4.7.3.1 Change in optical transmittance. This test shall evaluate the change of optical power

(transmittance) level of the fibers due to exposure to one or more inspection (mechanical and

environmental) tests (see 3.6.1). The wavelength tested shall be as specified in the applicable

specification sheet (see 3.1). The periodicity of the measurement shall be appropriate for the test method

(see measurement 2012 in MIL-STD-1678-2) and as approved by the qualifying activity.

4.7.3.1.1 Method. The change in optical transmittance shall be measured during and after the test

(from a baseline obtained before each test) per TIA/EIA-455-20 for transmitted power adhering strictly to

the setup and test procedure specified in Measurement 2102 of MIL-STD-1678-2.

4.7.3.2 Attenuation rate (see 3.6.2). The attenuation rate of each individual fiber shall be measured in

accordance with measurement 2106 of MIL-STD-1678-2.

4.7.3.2.1 Attenuation rate (for Type I fiber only). Light launch conditions utilizing beam optics preferred.

4.7.3.2.2 Attenuation rate (for Type II fiber only). Light launch conditions shall utilize a higher order

mode filter.

4.7.3.2.3 Attenuation uniformity. The attenuation uniformity of each individual fiber shall be measured

in accordance with TIA-455-78. Unless otherwise specified, the attenuation uniformity shall be measured

at a wavelength of 1300 nm (see 3.6.2.1).

4.7.3.3 Numerical aperture (for type I fiber only). The numerical aperture shall be determined in

accordance with TIA/EIA-455-177 (see 3.6.3).

4.7.3.4 Bandwidth (for type I fiber only). The Type I fiber bandwidth shall be determined for both

overfill and restricted (either RML or EMBc) launch in accordance with TIA/EIA-455-204. For restricted

launch, TIA-455-220 may be used in lieu of TIA/EIA-455-204. The bandwidth shall meet the

requirements specified in 3.1 and 3.6.4.

4.7.3.5 Macrobend attenuation. The macrobend attenuation of each individual fiber shall be measured

in accordance with TIA-455-62. Launch conditions shall be in accordance with 4.7.3.1.1. Macrobend

attenuation shall meet the requirements specified in 3.6.5.