SHG Polarization Anisotropy

Calculate parallel/perpendicular SHG ratio and polarization anisotropy.

Description

SHG polarization anisotropy compares parallel and perpendicular signals using a fixed denominator convention.

SHG polarization anisotropy compares parallel and perpendicular signals using a fixed denominator convention. The ratio and anisotropy summarize supplied measurements.^[1]

Calculate parallel/perpendicular SHG ratio and polarization anisotropy.

When to use SHG Polarization Anisotropy

Use this tool to calculate parallel/perpendicular SHG ratio and polarization anisotropy.

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 SHG Polarization Anisotropy 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 parallelIntensity, perpendicularIntensity using the field table and calculation rules, then run the tool.
Read parallelToPerpendicularRatio, anisotropy. 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
parallelIntensity	Parallel SHG intensity	number; minimum: 0	Required
perpendicularIntensity	Perpendicular SHG intensity	number; minimum: 0	Required

Enter nonnegative parallel and positive perpendicular intensity. Return ratio and anisotropy.

ratio=parallel/perpendicular; anisotropy=(parallel−perpendicular)/(parallel+2perpendicular)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
parallelToPerpendicularRatio	Parallel-to-perpendicular ratio	number; minimum: 0
anisotropy	SHG polarization anisotropy	number; minimum: -0.5; maximum: 1

json

{
  "input": {
    "parallelIntensity": 4,
    "perpendicularIntensity": 1
  },
  "output": {
    "parallelToPerpendicularRatio": 4,
    "anisotropy": 0.5
  }
}

Limitations and assumptions

No polarization calibration, molecular-orientation model or background correction 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 SHG Phase Match: Calculate SHG-style phase mismatch, coherence length, and normalized conversion efficiency. For a complementary task, use Photoacoustic Hemoglobin Contrast: Unmix two-wavelength photoacoustic signals into hemoglobin contributions and saturation.

References

SHG Polarization Anisotropy — tool.io

Similar or alternative tools

SHG Phase Match
Calculate SHG-style phase mismatch, coherence length, and normalized conversion efficiency.
Photoacoustic Hemoglobin Contrast
Unmix two-wavelength photoacoustic signals into hemoglobin contributions and saturation.