Fresnel Reflection Loss
Compute lossless real-index oblique Fresnel s/p energy reflection and transmission with explicit TIR; not normal-only lustre proxy, absorbing media or integrated gemstone light return.
Description
Fresnel reflection depends on incidence angle, refractive-index contrast and polarization.
Fresnel reflection depends on incidence angle, refractive-index contrast and polarization. A lossless real-index model separates reflected and transmitted energy and total internal reflection.1
Compute lossless real-index oblique Fresnel s/p energy reflection and transmission with explicit TIR; not normal-only lustre proxy, absorbing media or integrated gemstone light return.
When to use Fresnel Reflection Loss
Use this tool to compute lossless real-index oblique Fresnel s/p energy reflection and transmission with explicit TIR; not normal-only lustre proxy, absorbing media or integrated gemstone light return.
Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
How to use Fresnel Reflection Loss and understand its results
- Prepare the gemstone measurements, spectra or comparison data and any supplied calibration parameters. Check units, reference conditions and record alignment.
- Enter incidentIndex, transmittedIndex, incidenceDegrees using the field table and calculation rules, then run the tool.
- Read sPolarizedReflectance, pPolarizedReflectance, unpolarizedReflectance, idealTransmittedEnergyFraction, totalInternalReflection. 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 |
|---|---|---|---|
| incidentIndex | Incident index | number | Required |
| transmittedIndex | Transmitted index | number | Required |
| incidenceDegrees | Incidence degrees | number | Required |
Use positive incident/transmitted indices and incidence in [0°,90°). Apply Snell's law; if its transmitted sine is ≥1, return reflection 1, transmission 0 and TIR true. Otherwise report s/p reflectances, their mean and one minus that mean as transmission.
Rs=[(n1 cos i−n2 cos t)/(n1 cos i+n2 cos t)]²; Rp=[(n2 cos i−n1 cos t)/(n2 cos i+n1 cos t)]² Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| sPolarizedReflectance | S polarized reflectance | number |
| pPolarizedReflectance | P polarized reflectance | number |
| unpolarizedReflectance | Unpolarized reflectance | number |
| idealTransmittedEnergyFraction | Ideal transmitted energy fraction | number |
| totalInternalReflection | Total internal reflection | boolean |
{
"input": {
"incidentIndex": 1,
"transmittedIndex": 1.5,
"incidenceDegrees": 0
},
"output": {
"sPolarizedReflectance": 0.04000000000000001,
"pPolarizedReflectance": 0.04000000000000001,
"unpolarizedReflectance": 0.04000000000000001,
"idealTransmittedEnergyFraction": 0.96,
"totalInternalReflection": false
}
}Limitations and assumptions
Absorption, complex indices, multilayers and full gemstone return are excluded.
Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use Critical Angle: Resolve optical total-internal-reflection critical angle for a caller higher-to-lower-index interface; not seismic critical-angle appearance, prism/rainbow geometry or actual stone light return. For a complementary task, use Light Return Tilt Check: Trace supplied meridional entry and exit-facet normals measured relative to the same entry-face normal under declared tilt/index; zero exit angle is unused for TIR flags, and this local-interface screen is not full gemstone light-return simulation.
References
-
Fresnel Reflection Loss — tool.io
Similar or alternative tools
- Critical Angle
Resolve optical total-internal-reflection critical angle for a caller higher-to-lower-index interface; not seismic critical-angle appearance, prism/rainbow geometry or actual stone light return.
- Light Return Tilt Check
Trace supplied meridional entry and exit-facet normals measured relative to the same entry-face normal under declared tilt/index; zero exit angle is unused for TIR flags, and this local-interface screen is not full gemstone light-return simulation.