Optical signatures of a tightly confined Bose condensate

Optical properties of a Bose condensate of ${\mathit{N}}_{\mathit{c}}$ atoms tightly confined to a harmonic oscillator potential are studied. A resonantly illuminated condensate scatters as much light as x independent atoms, where x depends on the size of the condensate and on the wavelength of light but not on ${\mathit{N}}_{\mathit{c}}$; the linewidth of the resonance is ${\mathit{N}}_{\mathit{c}}$/x times larger than the linewidth of an individual constituent atom. If the condensate is bigger than a wavelength, light is predominantly scattered in the forward direction.