Template:SI photon units

Quantity Unit Dimension Notes
Name Symbol[nb 1] Name Symbol
photon energy n 1 count of photons n with energy Qp = hc/λ.[nb 2]
photon flux Φq count per second s−1 T−1 photons per unit time, dn/dt with n = photon number.
also called photon power
photon intensity I count per steradian per second sr−1⋅s−1 T−1 dn/dω
photon radiance Lq count per square metre per steradian per second m−2⋅sr−1⋅s−1 L−2T−1 d2n/(dA cos(θ) dω)
photon irradiance Eq count per square metre per second m−2⋅s−1 L−2T−1 dn/dA
photon exitance M count per square metre per second m−2⋅s−1 L−2T−1 dn/dA
See also:
  1. ^ Standards organizations recommend that photon quantities be denoted with a suffix "q" (for "quantum") to avoid confusion with radiometric and photometric quantities.
  2. ^ The energy of a single photon at wavelength λ is Qp = hc/λ with h = Planck constant and c = velocity of light.