Cherenkov Outcoupling Angle
Calculate a Cherenkov outcoupling angle from THz phase and optical group indices.
Description
This Cherenkov outcoupling calculation applies an arccosine to the supplied THz-phase-to-optical-group-index ratio.
This Cherenkov outcoupling calculation applies an arccosine to the supplied THz-phase-to-optical-group-index ratio. The returned flag describes that implemented ratio test.1
Calculate a Cherenkov outcoupling angle from THz phase and optical group indices.
When to use Cherenkov Outcoupling Angle
Use this tool to calculate a Cherenkov outcoupling angle from THz phase and optical group indices.
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 Cherenkov Outcoupling Angle 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 terahertzPhaseIndex, opticalGroupIndex using the field table and calculation rules, then run the tool.
- Read cherenkovAngleDegrees, phaseMatched. 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 |
|---|---|---|---|
| terahertzPhaseIndex | THz phase index | number; minimum: 0 | Required |
| opticalGroupIndex | Optical group index | number; minimum: 0 | Required |
Enter nonnegative THz index and positive optical group index. For ratio≤1 return degrees and true; for ratio>1 return zero with false.
ratio=THzPhaseIndex/opticalGroupIndex; angle=acos(ratio) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| cherenkovAngleDegrees | Cherenkov outcoupling angle (°) | number; minimum: 0; maximum: 90 |
| phaseMatched | Physical phase-matched angle | boolean |
{
"input": {
"terahertzPhaseIndex": 1,
"opticalGroupIndex": 2
},
"output": {
"cherenkovAngleDegrees": 60.00000000000001,
"phaseMatched": true
}
}Limitations and assumptions
Zero on failure is a placeholder. Verify the index ratio and angle convention for the actual geometry; the tool does not independently establish physical phase matching.
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. A successfully returned false flag is an evaluated outcome; its meaning is explained above.
Alternative or Complementary methods
Use Grating Steering Angle: Solve the scalar grating equation for diffraction angle. For a complementary task, use SHG Phase Match: Calculate SHG-style phase mismatch, coherence length, and normalized conversion efficiency.
References
-
Cherenkov Outcoupling Angle — tool.io
Similar or alternative tools
- Grating Steering Angle
Solve the scalar grating equation for diffraction angle.
- SHG Phase Match
Calculate SHG-style phase mismatch, coherence length, and normalized conversion efficiency.