  We study some basic quantum confinement effects through investigation a
deformed harmonic oscillator algebra. We show that spatial confinement effects
on a quantum harmonic oscillator can be represented by a deformation function
within the framework of nonlinear coherent states theory. Using the deformed
algebra, we construct a quantum field theory in confined space. In particular,
we find that the confinement influences on some physical properties of the
electromagnetic field and it gives rise to nonlinear interaction. Furthermore,
we propose a physical scheme to generate the nonlinear coherent states
associated with the electromagnetic field in a confined region.
