Dispersion-Shifted Fiber Calculator
Compare DSF, NZ-DSF, and DCF dispersion characteristics.
Results
entered length exceeds L_max
Limit: 4Bσ ≤ 1 on the output rms width, with the input pulse width chosen to minimise it (Agrawal; covers broad and narrow sources and β₃ at λ₀).
Formulas
D(λ) = D₁₅₅₀ + S·(λ − 1550 nm)
G.652: D(λ) = (S₀/4)(λ − λ₀⁴/λ³)
σ_D = L·√((Dσ_λ)² + ½(Sσ_λ²)²)
σ² ≈ σ_D² + |β₂|L (optimum input width), L_max: 4Bσ = 1
Model and references
Textbook approximation. A standard approximation from the literature (for example paraxial, plane-wave or Gaussian-beam), valid within the range the page states. About the tiers
Typical presets, linear about 1550 nm (G.652 uses its Sellmeier form), valid over 1460–1625 nm. Length limit 4Bσ ≤ 1 with the optimum input pulse. Attenuations are typical values; use your fibre's datasheet.
- ITU-T G.652 (11/2016). Characteristics of a single-mode optical fibre and cable. D(λ) = (S₀/4)(λ − λ₀⁴/λ³) with 1300 ≤ λ₀ ≤ 1324 nm and S₀ ≤ 0.092 ps/(nm²·km). itu.int
- ITU-T G.653. Characteristics of a dispersion-shifted single-mode optical fibre and cable (λ₀ near 1550 nm, S₀ ≤ 0.085 ps/(nm²·km)). itu.int
- ITU-T G.655. Characteristics of a non-zero dispersion-shifted single-mode optical fibre and cable (G.655.C: 1 ≤ |D| ≤ 10 ps/(nm·km) over 1530–1565 nm). itu.int
- Agrawal G. P. (2010). Fiber-Optic Communication Systems, 4th ed., §2.3–2.4. Wiley. doi:10.1002/9780470918524