Optics

Learn how light can be described as a ray or wave and how you manipulate light with lasers and optical lenses.

Formula

Numerical Aperture (Definition)

Minimum Distance Between Two Distinguishable Objects (Rayleigh Criterion)

Lesson

Physical Quantities and Their Units

List of important physical quantities, their symbols, (derived) units and examples with images.

Lesson

The 12 Important Physical Constants

Learn about important physical constants and what their formula symbols and SI units are.

Formula

Law of Reflection (Angle of Incidence, Angle of Reflection)

Reflection of Light on the Water Surface

Derivation

Double-Slit Formula

Here we derive the double-slit formula, which you can use, for example, to find the wavelength of light using a double-slit experiment.

Wavelength of a Complicated Shaped Periodic Wave

Frequency of a Sinusoidal Wave

Formula

Definition of the Wave Number

Formula

Relationship Between Wave Number and Angular Wave Number

Formula

Definition of the Angular Wavenumber

Wave Number of a Sinusoidal Wave

What is the Speed of Light?

What is Wavelength?

Formula

Total Internal Reflection (Critical Angle, Refractive Index)

Formula

Snell's Law (Angle of Incidence and Refraction, Refractive Index)

Light Beam with Angle of Incidence and Refraction for Snell's Law

What is the Refractive Index?

How do You Determine the Focal Length of a Lens?