Quantum optics

Photon energy
Ε = m c^2

Photon energy
E = h ν

Photon energy
E = h c / λ

Photon energy
Ε = ℏ ω

Small Planck constant
ℏ = h / (2π)

Photon impulse
p = m c

Photoeffect: decelerating(retarding) voltage
m v^2 / 2 = e U

Photoeffect: energy conservation law
h ν = A + m v^2 / 2

Photoeffect: red limit
h ν = A

Photoeffect: red limit: light wave length
h c / λ = A

Light pressure
p = P_0 (1+R) / c

Power of the incident electromagnetic wave
P_0 = E / (S t)