General

This procedure describes three methods by which the angular radiant intensity (far field) distribution from an optical fiber can be measured. Methods A and B are angular scans of the far field pattern; Method C is a scan of the spatial transform of the angular intensity pattern.

Numerical Aperture

This measurement method can be used to collect data that may be used in conjunction with FOTP-177 to determine the numerical aperture of graded-index multimode optical fibers.

Hazards

This method may employ laser sources and requires fiber alignment. Conform the design and operation of test equipment to the requirements of ANSI Z136.1 and/or Z136.2.