  We consider the transformation for the point rotation frames with the angle,
spatial coordinate along the axis of rotation and time as variables. The
problem arises when light, propagating through 3-fold electrooptical crystal,
is modulated by the circularly polarized electromagnetic wave traveling along
the optical axis of the crystal. With help of the transformation we show that
such a wave cannot produce an extra optical frequency shift discussed earlier.
In contrast to that the modulation by the rotating spatially invariable
electric field produces the shift. The formal change to this case may be
carried out by reducing the velocity of the traveling wave to zero. Some
properties of the three-dimensional transformation are discussed.
