\[\theta_c=\sin^{-1}\left(\frac{n_2}{n_1}\right)\]
Variables
thetaC[θc]critical angle
n1refractive index of incident medium
n2refractive index of transmitted medium
Description
What is this formula?
This formula calculates the critical angle at the interface between two media. When light reaches an angle greater than the critical angle, total internal reflection occurs.
When to use it
Use this formula when analyzing fiber optics, optical waveguides, prisms, and light propagation between different materials.
Example
Given:
n1=1.50
n2=1.00
Formula:
θc=sin⁻¹(n2/n1)
Substitution:
θc=sin⁻¹(1.00/1.50)
Result:
θc=41.8°
Applications
- Fiber optic communication
- Optical sensors
- Prism design
- Internal reflection systems
- Optical engineering