Hello everyone:(adsbygoogle = window.adsbygoogle || []).push({});

Here is the problem:

Under thermal equilibrium, photon's number can be described as the

photonic density of state (PDOS) * occupation number(ON).

Also, the photon's flux can be described as

PDOS * ON * effective particle velocity into certain direction ( V)

The occupation number is determined by the source, typically it will be a Boltzmann distribution characterized by the temperature and chemical potential.

When a beam scattering by an interface between media 1 and media 2, only part of incident energy can go through into the second media. If we continuously tracing the energy of the photon flux, we may can write the following equation:

PDOS1* ON(IN) * V1 = .PDOS2 * ON(T) * V2 + PDOS1 * ON(R) * V1

, where IN, T, R means incidence, transmission and reflection respectively.

This means the occupation number of photon in the media 2 will be different to the one in media 1. Is such an effective occupation number is meaningful and this consideration is correct? Does this mean that once the reflection happens the occupation number of photon in media 2 will never reach the thermodynamic limit?

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Effective occupation number of photon

Loading...

Similar Threads - Effective occupation number | Date |
---|---|

I Question about gauge invariance and the A-B effect | Mar 3, 2018 |

I What is the spin Hall effect | Feb 19, 2018 |

I Effect of momentum distribution on probability density | Feb 1, 2018 |

I Checking the effect an operator has on a state | Jan 15, 2018 |

Mean Occupation Number of Non-interacting quantum fluids | Mar 7, 2014 |

**Physics Forums - The Fusion of Science and Community**