Energy sources with the uniform intensity distribution are used in holography, measuring techniques, optical processors, laser technology, etc. Such sources can be obtained b different intracavity methods, one of the most advantageous of which is the use of phase diffraction gratings (DGs) 'it A new class of beam shapers in the form of DGs with a complex rectangular groove disposition period T is proposed within which an odd number of scat- tering elements are located. The beam shaper geometries are shown in Fig.l. AT,. and AT I are the distances from the structure axis to the centers of the left-hand and right-hand periods adjacent to the disturbance location. With v = 3, 7, 15, ..., d2= d3,di = 2d2 DGs are described by a set of Walsh functions Wa/m(x). The latters are presented in terms of Rademacher functions Rk(x) product 3'2. The specific feature of proposed DGs is their capability of concentrating energy in one or several diffraction orders. The maximum energy order number n1 is equal to v. With v < 7 the diffracted field energy is concentrated in two adjacent orders. The number of the second order (with lower intensity) equals v + 2. The choice of the DG period number N is determined by the optimum overlapping of the most intensive diffraction orders and depends on the angular beam divergence e 0.