  A simple analytical way of creating superpositions of Bessel-Gaussian light
beams with knotted nodal lines is proposed. It is based on the equivalence
between the paraxial wave equation and the two-dimensional Schr\"odinger
equation for a free particle. The $2D$ Schr\"odinger propagator is expressed in
terms of Bessel functions, which allows to obtain directly superpositions of
beams with a desired topology of nodal lines. Four types of knots are
constructed in the explicit way: the unknot, the Hopf link, the Borromean rings
and the trefoil. It is also shown, using the example of the figure-eight knot,
that more complex structures require larger number of constituent beams as well
as high precision both from the numerical and the experimental side. A tiny
change of beam's intensity can lead to the knot "switching".
