LIDT Scaling Calculator
Scale laser-induced damage threshold values between test and application conditions, calculate operating fluence, and verify safety margins.
Laser-induced damage threshold (LIDT) values published in optics datasheets are measured under specific test conditions — wavelength, pulse duration, and beam size — that rarely match the application. The ISO 21254 scaling law adjusts published LIDT values via LIDT₂ ≈ LIDT₁ × (λ₂/λ₁) × √(τ₂/τ₁) × (∅₁/∅₂)², where the square-root pulse duration scaling applies to nanosecond pulses in the thermally dominated regime. This calculator accepts test and application conditions, computes each scaling factor, and returns the adjusted LIDT at application conditions along with a derated value divided by a user-specified safety factor. An optional fluence check compares the operating peak fluence — calculated from pulse energy and beam size for Gaussian or flat-top profiles — against the derated LIDT and flags pass, warning, or fail. A CW mode evaluates linear power density in W/cm against a CW LIDT specification.
Note: Pulsed LIDT scaling uses √τ and is valid only for nanosecond/microsecond pulses (roughly 1 ns to 100 ns). Do not apply to sub-nanosecond (ultrafast) pulses. Beam diameter scaling is approximate and may overestimate the reduction for beams larger than ~5 mm.