Formula Explanation

The coherence length is approximated by:

L_c ≈ 0.886 × (λ₀² / Δλ)

where:

• λ₀ is the central wavelength (nm).
• Δλ is the full width at half maximum (FWHM) in wavelength (nm).

This expression estimates the coherence length for a Gaussian spectral distribution. The result is displayed in millimeters (mm).