1. What is Refractive Index?

The refractive index (n) of a material is a dimensionless number that describes how light propagates through that 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 refractive index formula:

Where:

• \( n \) — Refractive index (dimensionless)
• \( c \) — Speed of light in vacuum (299,792,458 m/s)
• \( v \) — Speed of light in the medium (m/s)

Example: For glass where light travels at 197,000,000 m/s, n ≈ 1.52

3. Importance of Refractive Index

Details: The refractive index determines how much light bends when entering a material (refraction), which is crucial for lens design, optical fibers, and understanding material properties.

4. Using the Calculator

Tips: Enter the speed of light in the medium in meters per second (must be positive and less than speed of light in vacuum).

5. Frequently Asked Questions (FAQ)

Q1: What is the refractive index of window glass?
A: Approximately 1.52, meaning light travels about 1.52 times slower in glass than in vacuum.

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 special cases with anomalous dispersion, effective n can appear <1.

Q3: Why is refractive index important for windows?
A: It determines how much light bends when entering/leaving the glass, affecting clarity and potential reflections.

Q4: How does temperature affect refractive index?
A: Generally, refractive index decreases slightly with increasing temperature as the material becomes less dense.

Q5: What materials have the highest refractive index?
A: Diamond has n≈2.42, while some engineered metamaterials can have much higher values.