Amo Calculator

Photon Energy, Frequency, and Wavelength Calculator

This calculator helps you determine the fundamental properties of a photon: its energy, frequency, and wavelength. These relationships are central to Atomic, Molecular, and Optical (AMO) physics, describing how light interacts with matter.

Enter a value in one of the fields below to calculate the others:

Understanding Photon Properties in AMO Physics

Atomic, Molecular, and Optical (AMO) physics is a field that studies the interaction of matter and light at the scale of individual atoms and molecules. A fundamental concept in AMO is the photon, the quantum of light, which exhibits both wave-like and particle-like properties. The energy, frequency, and wavelength of a photon are intrinsically linked by universal physical constants.

The Fundamental Relationships

The core equations governing these properties are:

• Energy (E) and Frequency (f): E = hf
• Speed of Light (c), Frequency (f), and Wavelength (λ): c = fλ

Where:

• E is the photon energy, typically measured in Joules (J) or electronvolts (eV).
• h is Planck's constant, approximately 6.62607015 × 10^-34 J·s.
• f is the photon frequency, measured in Hertz (Hz).
• c is the speed of light in a vacuum, approximately 299,792,458 m/s.
• λ (lambda) is the photon wavelength, measured in meters (m).

Units and Conversions

For convenience in AMO physics, different units are often used:

• Wavelength: Commonly expressed in nanometers (nm), where 1 nm = 10^-9 m.
• Frequency: Often in Terahertz (THz), where 1 THz = 10¹² Hz.
• Energy: While Joules (J) are the SI unit, electronvolts (eV) are frequently used, especially when dealing with atomic and molecular energy levels. 1 eV is the amount of kinetic energy gained by a single electron accelerating through an electric potential difference of one volt. The conversion factor is approximately 1 eV = 1.602176634 × 10^-19 J.

How the Calculator Works

This calculator allows you to input any one of these properties (wavelength, frequency, or energy in eV) and it will compute the other related values. It uses the fundamental constants and unit conversions to provide results in commonly used units.

Examples:

Example 1: Green Laser Pointer

A common green laser pointer emits light with a wavelength of 532 nm.

• Input: Wavelength = 532 nm
• Output:
  • Frequency ≈ 563.5 THz
  • Energy ≈ 3.73 × 10^-19 J
  • Energy ≈ 2.33 eV

Example 2: UV Light for Sterilization

UV-C light used for sterilization often has a frequency around 1.2 × 10¹⁵ Hz (or 1200 THz).

• Input: Frequency = 1200 THz
• Output:
  • Wavelength ≈ 249.8 nm
  • Energy ≈ 7.95 × 10^-19 J
  • Energy ≈ 4.96 eV

Example 3: Energy of a Hydrogen Atom Transition

The energy difference for the Balmer alpha transition (n=3 to n=2) in hydrogen is approximately 1.89 eV.

• Input: Energy = 1.89 eV
• Output:
  • Wavelength ≈ 656.3 nm
  • Frequency ≈ 456.8 THz
  • Energy ≈ 3.03 × 10^-19 J