Optics CheatSheet

Geometric Optics

Law of Reflection

The angle of incidence () is equal to the angle of reflection ().

Snell’s Law

Laws of Refraction

Where:

• andare the refractive indices of media 1 and 2.
• is the angle of incidence.
• is the angle of refraction.

Lens Equations

Thin Lens Equation

Where:

• is the focal length of the lens.
• is the distance of the object to the lens.
• is the distance of the image to the lens.

Lens Magnification

Where:

• is the height of the image.
• is the height of the object.

Mirror Equations

Plane Mirror Equation

Spherical Mirror Equation

Mirror Magnification

Physical Optics

Interference

Condition for Constructive Interference

Where:

• is the separation between the slits.
• is the angle of diffraction.
• is the order of interference.
• is the wavelength.

Condition for Destructive Interference

Diffraction

Single-Slit Diffraction Equation

Where:

• is the width of the slit.
• is the order of diffraction.

Polarization

Malus’s Law

Where:

• is the intensity of the light after passing through the polarizer.
• is the initial intensity.
• is the angle between the direction of light and the polarization axis.

Quantum Optics

Photoelectric Effect

Photon Energy

Where:

• is the energy of the photon.
• is Planck’s constant ().
• is the frequency of light.

Kinetic Energy of Electrons

Where:

• is the work function.

Spectroscopy

Relationship between wavelength and energy

Where:

• is the speed of light ().
• is the wavelength.