OVALITY

1. The attribute of an optical fiber , the cross section of the core or cladding of which deviates from a perfect circle. 2. In an optical fiber, the degree of deviation, from perfect circularity, of the cross section of the core or cladding. Note 1: The cross sections of the core and cladding are assumed to first approximation to be elliptical. Quantitatively, the ovality of either the core or cladding is expressed as 2( a - b )/( a + b ), where a is the length of the major axis and b is the length of the minor axis. The dimensionless quantity so obtained may be multiplied by 100 to express ovality as a percentage. Note 2: Alternatively, ovality of the core or cladding may be expressed or specified by a tolerance field consisting of two concentric circles, within which the cross section boundaries must lie. Synonym noncircularity.