Fiber splice loss calculator

Input

μm

°

Output

μm

μm

%

dB

About this calculator

This calculator computes the splice loss between two single mode fibers assuming Gaussian mode shapes according to Marcuse's equation (see Mode field diameter calculator). The splice loss in dB is computed as

Loss(dB)=10log[4w12w22(w12+w22)2exp(4δ2+k02n2w12w22sin2θ2(w12+w22))]Loss(dB) = -10\log\left[\dfrac{4 w_1^2 w_2^2}{(w_1^2 + w_2^2)^2}\exp\left(-\dfrac{4\delta^2 + k_0^2 n ^2 w_1^2 w_2^2 \sin^2 \theta}{2(w_1^2 + w_2^2)} \right)\right]

where w1w_1 and w2w_2 are the mode field radii in fibers 1 and 2, respectively. δ\delta is the lateral offset between the fibers' cores, θ\theta is the angular offset between the cores, k0=2πλk_0=\dfrac{2\pi}{\lambda} is the vacuum wave number and nn is the refractive index of the fibers' cores.

The splice loss is the same independent of which fiber is the input fiber and which the output fiber. This formula works best for standard fibers with relatively large V-parameters whose mode field can be well approximated as Gaussian.