  In this paper, we derive the dynamical algebra of a particle confined in an
infinite spherical well by using the $f$-deformed oscillator approach. We
consider an exciton with definite angular momentum in a wide quantum dot
interacting with two laser beams. We show that under the weak confinement
condition, and quantization of the center-of-mass motion of exciton, the
stationary state of it can be considered as a special kind of nonlinear
coherent states which exhibits the quadrature squeezing.
