Practical microbending loss formula for single-mode optical fibers

Microbending loss in a step-index single-mode fiber is formulated in an expression which provides an explicit dependence on wavelength λ and relative index difference Δ. For the permissible mean bending radius
R\dagger
corresponding to a given loss,
\Delta^{3/2}R\dagger/\lambda
is the function
f
of only a normalized frequency υ. This property resembles that for the uniform-bending loss. However,
f
in the microbending loss depends less critically on υ than in the uniform-bending loss.