It is possible to enhance the efficiency of diffractive optical elements(DOE), by multilevel structures, blazed structures, or by high frequency gratings. But for some purposes, in one DOE, one part is with 'big' structures and another part with 'small' structures. For example, the reflective beam shaping DOE for stripe laser diode. In this case, if only using the multilevel structures or blazed structures for the whole DOE, in 'small' structure area, is not easy to fabricate. On the other side, if only using binary structures for the whole DOE, in 'big' structures, the efficiency is not high enough. We propose a new method to combine the two structures in one DOE, for high efficiency and convenient fabrication.
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