1. What is the Index of Refraction?

The index of refraction (n) is a dimensionless number that describes how light propagates through a medium. It's defined as the ratio of the speed of light in vacuum to the speed of light in the medium.

2. How Does the Calculator Work?

The calculator uses the index of refraction formula:

Where:

• \( n \) — Index of refraction (dimensionless)
• \( c \) — Speed of light in vacuum (3 × 10⁸ m/s)
• \( v \) — Speed of light in the medium (m/s)

Explanation: The higher the refractive index, the more the light is slowed down and bent when entering the material.

3. Importance of Refractive Index

Details: The refractive index is crucial in optics for designing lenses, understanding light behavior in different media, and in technologies like fiber optics and spectroscopy.

4. Using the Calculator

Tips: Enter the speed of light in vacuum (typically 3 × 10⁸ m/s) and the speed of light in the medium. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical values for refractive index?
A: Air: ~1.0003, Water: ~1.33, Glass: ~1.5-1.9, Diamond: ~2.42.

Q2: Can refractive index be less than 1?
A: Normally no, as this would imply light travels faster than in vacuum, which violates relativity. However, in some metamaterials, effective refractive index can appear <1.

Q3: Does refractive index depend on wavelength?
A: Yes, this is called dispersion. Shorter wavelengths (blue light) typically have higher refractive indices than longer wavelengths (red light).

Q4: How is refractive index measured experimentally?
A: Common methods include using a refractometer, measuring critical angle, or observing light bending at interfaces.

Q5: Why is refractive index important in lenses?
A: The refractive index determines how much light bends when entering the lens material, affecting the lens's focal length and optical power.