Henry Alpha
Estimate the Henry linewidth-enhancement factor from wavelength and modal-gain changes.
Description
A linewidth-enhancement-factor estimate relates wavelength change to modal gain change with a fixed sign convention.
A linewidth-enhancement-factor estimate relates wavelength change to modal gain change with a fixed sign convention. Both changes must refer to the intended common perturbation.1
Estimate the Henry linewidth-enhancement factor from wavelength and modal-gain changes.
When to use Henry Alpha
Use this tool to estimate the Henry linewidth-enhancement factor from wavelength and modal-gain changes.
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 Henry Alpha 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 centerWavelengthMeters, wavelengthChangeMeters, modalGainChangePerMeter using the field table and calculation rules, then run the tool.
- Read wavelengthGainSlopeM2, linewidthEnhancementFactor. 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 |
|---|---|---|---|
| centerWavelengthMeters | Center wavelength (m) | number; minimum: 0 | Required |
| wavelengthChangeMeters | Wavelength change (m) | number | Required |
| modalGainChangePerMeter | Modal gain change (1/m) | number | Required |
Enter positive center wavelength and finite signed changes with nonzero gain change. Return slope in m² and alpha.
slope=Δλ/Δgain; alpha=−4πslope/λcenter² Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| wavelengthGainSlopeM2 | Wavelength-to-gain slope (m²) | number |
| linewidthEnhancementFactor | Henry alpha factor | number |
{
"input": {
"centerWavelengthMeters": 2,
"wavelengthChangeMeters": -1,
"modalGainChangePerMeter": 3.141592653589793
},
"output": {
"wavelengthGainSlopeM2": -0.3183098861837907,
"linewidthEnhancementFactor": 1
}
}Limitations and assumptions
No carrier-density fit, device calibration or linewidth calculation is performed.
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 MZM Chirp: Estimate Mach–Zehnder modulator chirp from phase and power modulation. For a complementary task, use Relaxation-Oscillation Frequency: Estimate relaxation-oscillation frequency from normalized drive and photon and carrier lifetimes.
References
-
Henry Alpha — tool.io
Similar or alternative tools
- MZM Chirp
Estimate Mach–Zehnder modulator chirp from phase and power modulation.
- Relaxation-Oscillation Frequency
Estimate relaxation-oscillation frequency from normalized drive and photon and carrier lifetimes.