Optogalvanic Modulation Contrast
Calculate optogalvanic modulation amplitude and normalized contrast.
Description
Optogalvanic modulation compares laser-on and laser-off signals.
Optogalvanic modulation compares laser-on and laser-off signals. Two normalizations use the off signal and the sum respectively.1
Calculate optogalvanic modulation amplitude and normalized contrast.
When to use Optogalvanic Modulation Contrast
Use this tool to calculate optogalvanic modulation amplitude and normalized contrast.
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 Optogalvanic Modulation Contrast 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 laserOnSignal, laserOffSignal using the field table and calculation rules, then run the tool.
- Read modulationAmplitude, relativeContrastPercent, normalizedDifference. 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 |
|---|---|---|---|
| laserOnSignal | Laser-on electrical signal | number | Required |
| laserOffSignal | Laser-off electrical signal | number | Required |
Enter finite signed signals with nonzero off signal and nonzero sum. Return signed amplitude and normalized contrasts.
difference=on−off; relative%=100difference/off; normalized=difference/(on+off) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| modulationAmplitude | Optogalvanic modulation amplitude | number |
| relativeContrastPercent | Relative modulation contrast (%) | number |
| normalizedDifference | Normalized difference | number |
{
"input": {
"laserOnSignal": 120,
"laserOffSignal": 100
},
"output": {
"modulationAmplitude": 20,
"relativeContrastPercent": 20,
"normalizedDifference": 0.09090909090909091
}
}Limitations and assumptions
No discharge dynamics, background correction or spectroscopy fit 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 WMS 2f Error Signal: Resolve a wavelength-modulation 2f signal into amplitude, phase, and normalized lock error. For a complementary task, use SRS Contrast: Calculate stimulated Raman loss contrast from pump-on and pump-off probe measurements.
References
-
Optogalvanic Modulation Contrast — tool.io
Similar or alternative tools
- WMS 2f Error Signal
Resolve a wavelength-modulation 2f signal into amplitude, phase, and normalized lock error.
- SRS Contrast
Calculate stimulated Raman loss contrast from pump-on and pump-off probe measurements.