Apodized diffractive elements obtained with the help of HEBS glasses G. Adamkiewicz Institute of Electronics Materials Technology, Wólczyńska 133, 01-919 Warsaw, Poland Z. Jaroszewicz Institute of Applied Optics, Kamionkowska 18, 03-805 Warsaw, Poland and National Institute of Telecommunications, Szachowa 1, 04-894 Warsaw, Poland. A. Kołodziejczyk Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland. T. Osuch National Institute of Telecommunications, Szachowa 1, 04-894 Warsaw, Poland. mmtzjaroszewicz@post.pl 1 Introduction The conventional apodization of optical elements is realized usually by an application of amplitude masks. In the case of diffractive optical elements there appears an additional possibility, which can be realized by a local change of their diffraction efficiency. In the case of binary amplitude gratings it can be done by the duty ratio change [1], [2], whereas in the case of the binary phase grating by splitting the phase step [3]. In turn, for the multi-step lithographic elements the variable diffraction efficiency can be achieved by a gradual transformation of the kinoform into its conjugate across the apodization region [4]. The first experimental confirmation of this idea was performed with the help of SLM’s, where the apodized quaternary grating with locally varying diffraction efficiency was programmed by changing gradually the period’s profile [5]. In the present contribution we present preliminary work aimed at manufacture of such elements with the help of HEBS (High Energy Beam Sensitive) glasses. 2 Transformation of the multi-step diffractive element into its conjugate The ways, in which the L=2 N steps of a kinoform are modified in order to encode the apodization function, were described in detail in [4] and [5]. In our case we have adopted the solution proposed in [5], where every odd step is increased by π/2 along its length, whereas the even ones are decreased by the same quantity. In this way the quaternary grating shown in Fig. 1 (left), in the centre of the apodization region becomes converted into a binary phase one and at the end of the apodization region by further increase of odd steps and decrease of even ones becomes the conjugated quaternary grating (right). Figure 1: Conversion of the quaternary grating into its conjugate through the intermediate stage of binary phase grating by gradually decreasing phase heights of the even steps and increasing the odd steps by π/2 rad. 0 2π