In this paper, the tendency is towards looking for a correction factor in the diffraction loss from (TEM01) in order to search for the same parameters, diffraction loss in a cavity has standing (TEM01) modes. This will be through a lengthy analysis in the far-field intensities the waves via – Gaussian beam shaped wave patterns. The analysis is in the same criteria as that of (TEM00) modes, except for a little complicating factor in the round-trip by pass on the surface of the aperture mirror. The results showed that the diffraction loss procedure is just the continuate for the earlier work, except that the field intensities change for TEM01, as that of TEM00, as such, it has a direct effect on the equation fitting it. The Combination of experimental and Theoretical results in this study are in excellent agreement as in g = 0.80 and they were both functions of the physical parameters of the active medium and the laser resonator.