Fraunhofer diffraction pattern from a circular aperture with the diameter of 10µm was observed using an optical fiber microprobe. The optical fiber microprobe started to detect optical power when the distance between the probe and the circular aperture was more than 292µm. When the probe was moved in a lateral motion, the light propagation showed a Bessel function profile. When the optical fiber microprobe was moved from 293µm to 309µm from the centre of the circular aperture in a transverse motion, the power detected was not consistent with a continuation of maxima and minima due to the effect of light propagation from the circular aperture. We also observed that the distance between the probe and the centre of the circular aperture was directly proportional with the radius of focused spot and inversely proportional with the Fresnel number.