Fiber Coupling Efficiency Calculator
Estimate Gaussian beam to single-mode fiber coupling efficiency from beam waist, fiber MFD, and alignment offsets. Uses paraxial mode overlap.
Lensed-fiber typical: 2–6 μm. Collimated SMF: ~5.2 μm at 1310 nm.
SMF-28: 9.2 μm @ 1310 nm, 10.4 μm @ 1550 nm. HI-1060: 6.2 μm @ 1060 nm.
Excellent. Near-optimal mode match.
Black dot shows current position. Solid line is efficiency sweep at fixed beam waist and longitudinal offset.
Computed from the paraxial mode overlap integral for two Gaussian modes. Size mismatch term: η_size = (2 w_b w_f / (w_b² + w_f²))². Lateral offset term: η_x = exp(-2x² / (w_b² + w_f²)). Longitudinal offset modeled as Rayleigh-range beam expansion. Estimates do not include angular mismatch or surface reflections.
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