  We introduce the negative binomial states with negative binomial distribution
as their photon number distribution. They reduce to the ordinary coherent
states and Susskind-Glogower phase states in different limits. The ladder and
displacement operator formalisms are found and they are essentially the
Perelomov's su(1,1) coherent states via its Holstein-Primakoff realisation.
These states exhibit strong squeezing effect and they obey the super-Poissonian
statistics. A method to generate these states is proposed.
