Compute photon energy E = hν = hc/λ from frequency or wavelength, for single-photon energy conversion in optics, atomic physics and photodetection.
由频率或波长求光子能量。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Photon energy | E = hν = hc/λ | Planck 1900 |
| Handy conversion | E(eV) = 1240/λ(nm) | Spectroscopy formula |
| Inverse wavelength | Shorter wavelength → higher energy | EM spectrum |
| Planck constant | h = 6.62607015×10⁻³⁴ J·s | SI 2019 |
| Electronvolt | 1 eV = 1.602176634×10⁻¹⁹ J | SI units |
| Per mole | E_m = N_A hν (einstein) | Photochemistry terms |
Constants used on this page and their authoritative sources, for verification and citation
| Constant | Value | Unit | Source |
|---|---|---|---|
| Planck constant h | 6.62607015 × 10⁻³⁴ | J·s | SI defining constant (exact) |
| Speed of light in vacuum c | 299 792 458 | m·s⁻¹ | SI defining constant (exact) |
| Elementary charge e | 1.602176634 × 10⁻¹⁹ | C | SI defining constant (exact) |
Note: h, c and e are exact defining constants of the revised SI (2019); with 1 eV = e joule, E(eV) = hc/(λ·e).