Home Back

Cauchy Coefficient Formula

Cauchy Coefficient Formula:

\[ C = \frac{n^2 - 1}{(n - 1)^3} \]

dimensionless

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Cauchy Coefficient Formula?

The Cauchy Coefficient Formula calculates the dispersion coefficient in optics, which describes how the refractive index of a material varies with wavelength. It is particularly useful for characterizing optical materials and their dispersion properties.

2. How Does the Calculator Work?

The calculator uses the Cauchy Coefficient formula:

\[ C = \frac{n^2 - 1}{(n - 1)^3} \]

Where:

Explanation: The formula relates the refractive index to the dispersion coefficient, which quantifies how much light is spread out when passing through a material.

3. Importance of Cauchy Coefficient

Details: The Cauchy coefficient is crucial in optics for designing lenses, prisms, and other optical components. It helps predict chromatic aberration and optimize optical systems for different wavelengths of light.

4. Using the Calculator

Tips: Enter the refractive index value. The value must be greater than 0 and cannot be exactly 1 (as this would cause division by zero in the denominator).

5. Frequently Asked Questions (FAQ)

Q1: What is the physical significance of the Cauchy coefficient?
A: The Cauchy coefficient characterizes the material's dispersion - how its refractive index changes with wavelength, which affects color separation in optical systems.

Q2: What are typical values for refractive index?
A: Common values range from about 1.0 (air) to 1.33 (water), 1.5 (glass), and up to 2.4-2.6 for diamonds and some specialized optical materials.

Q3: Why can't n be exactly 1?
A: When n=1, the denominator becomes (1-1)³ = 0, resulting in division by zero, which is mathematically undefined.

Q4: How does this relate to the Cauchy dispersion equation?
A: This coefficient is part of the broader Cauchy dispersion equation that describes how refractive index varies with wavelength: n(λ) = A + B/λ² + C/λ⁴ + ...

Q5: What materials have high Cauchy coefficients?
A: Materials with strong dispersion properties, such as flint glass and certain crystals, typically have higher Cauchy coefficients compared to crown glass or fused silica.

Cauchy Coefficient Formula© - All Rights Reserved 2025