Tool 512 · Electromagnetic conversion
Wavelength · Frequency · Energy
Convert any one photon quantity into the rest, identify the approximate spectrum region, account for wavelength inside a refractive medium, or turn pulse energy / optical power into photon counts.
Exact SI constantsc, h, e and Nₐ use exact defining values.
Beyond 3 fieldsWavenumber, momentum, period, ω and molar photon energy.
Medium-awareFrequency stays fixed while wavelength changes with refractive index.
Photon budgetPhotons from radiant energy or power × duration.
Convert one known photon quantity
Choose wavelength, frequency, energy or wavenumber. Everything else is derived from exact SI definitions.
Known quantity
Wavelength inside a medium
This uses a supplied phase refractive index n. It does not predict dispersion or group velocity. Frequency and photon energy stay unchanged at a passive interface; phase wavelength becomes λ₀/n.
Photon wavelength / energy
Radiant quantity
Photon count assumes monochromatic radiant energy at the entered wavelength. For broadband sources, integrate over the spectrum instead of using a single representative wavelength.