Fizeau Frequency Precision
Estimate Fizeau wavemeter precision from scan span, FFT size, and interpolation precision.
Description
A frequency-bin precision estimate divides a supplied scan span by FFT sample count.
A frequency-bin precision estimate divides a supplied scan span by FFT sample count. A chosen sub-bin fraction scales that bin width.1
Estimate Fizeau wavemeter precision from scan span, FFT size, and interpolation precision.
When to use Fizeau Frequency Precision
Use this tool to estimate Fizeau wavemeter precision from scan span, FFT size, and interpolation precision.
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 Fizeau Frequency Precision 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 scanSpanHertz, sampleCount, subBinPrecisionFraction using the field table and calculation rules, then run the tool.
- Read fftBinWidthHertz, estimatedPrecisionHertz. 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 |
|---|---|---|---|
| scanSpanHertz | Frequency scan span (Hz) | number; minimum: 0 | Required |
| sampleCount | FFT sample count | integer; minimum: 2 | Required |
| subBinPrecisionFraction | Sub-bin precision fraction | number; minimum: 0; maximum: 1 | Required |
Enter nonnegative Hz span, integer samples≥2 and fraction 0–1. Return bin width and estimated precision.
binWidth=span/sampleCount; precision=binWidth×fraction Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| fftBinWidthHertz | FFT bin width (Hz) | number; minimum: 0 |
| estimatedPrecisionHertz | Estimated frequency precision (Hz) | number; minimum: 0 |
{
"input": {
"scanSpanHertz": 1000,
"sampleCount": 100,
"subBinPrecisionFraction": 0.1
},
"output": {
"fftBinWidthHertz": 10,
"estimatedPrecisionHertz": 1
}
}Limitations and assumptions
No FFT, interpolation fit, absolute wavemeter calibration or uncertainty proof is supplied.
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 FBG Peak Interpolation: Interpolate an FBG spectral peak from three equally spaced power samples. For a complementary task, use Comb Traceability Uncertainty: Combine independent fractional uncertainties in an optical-frequency traceability chain.
References
-
Fizeau Frequency Precision — tool.io
Similar or alternative tools
- FBG Peak Interpolation
Interpolate an FBG spectral peak from three equally spaced power samples.
- Comb Traceability Uncertainty
Combine independent fractional uncertainties in an optical-frequency traceability chain.