SLD Coherence Length
Estimate Gaussian SLD coherence length from center wavelength and spectral FWHM.
Description
A Gaussian-spectrum coherence-length estimate scales center wavelength squared by inverse spectral FWHM.
A Gaussian-spectrum coherence-length estimate scales center wavelength squared by inverse spectral FWHM. This defines the width convention used by the tool.1
Estimate Gaussian SLD coherence length from center wavelength and spectral FWHM.
When to use SLD Coherence Length
Use this tool to estimate Gaussian SLD coherence length from center wavelength and spectral FWHM.
Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
How to use SLD Coherence Length and understand its results
- Prepare the optical measurements, geometry, fitted coefficients or caller-selected thresholds requested. Confirm wavelength, radius/diameter, pulse-width, angle and unit conventions before running the calculation.
- Enter centerWavelengthNanometers, spectralWidthNanometers using the field table and calculation rules, then run the tool.
- Read coherenceLengthNanometers, coherenceLengthMicrometers. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| centerWavelengthNanometers | Center wavelength (nm) | number; minimum: 0 | Required |
| spectralWidthNanometers | Spectral FWHM (nm) | number; minimum: 0 | Required |
Enter nonnegative center wavelength and positive spectral width in nm. Return coherence length in nm and µm.
length=(2ln2/π)λcenter²/Δλ Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| coherenceLengthNanometers | Gaussian coherence length (nm) | number; minimum: 0 |
| coherenceLengthMicrometers | Gaussian coherence length (µm) | number; minimum: 0 |
{
"input": {
"centerWavelengthNanometers": 800,
"spectralWidthNanometers": 20
},
"output": {
"coherenceLengthNanometers": 14120.678409769704,
"coherenceLengthMicrometers": 14.120678409769704
}
}Limitations and assumptions
No actual spectrum, dispersion or alternative coherence-width convention is fitted.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use OCT Axial Resolution: Estimate Gaussian-spectrum OCT axial resolution in air and sample. For a complementary task, use Fabry-Pérot Linewidth: Calculate Fabry–Pérot free spectral range and linewidth from cavity length, index, and finesse.
References
-
SLD Coherence Length — tool.io
Similar or alternative tools
- OCT Axial Resolution
Estimate Gaussian-spectrum OCT axial resolution in air and sample.
- Fabry-Pérot Linewidth
Calculate Fabry–Pérot free spectral range and linewidth from cavity length, index, and finesse.