By virtue of density operator's P-representation in the coherent state representation, we derive a new quantum mechanical photon counting distribution formula. As its application, we find the photon counting distribution for the pure squeezed state relates to the Legendre function, which seems a new result.
@article{arxiv.1011.4402,
title = {A new quantum mechanical photon counting distribution formula},
author = {Hong-yi Fan and Hong-chun Yuan and Li-yun Hu},
journal= {arXiv preprint arXiv:1011.4402},
year = {2010}
}