An influence of period structure of binary phase diffractive axicon on an amplitude distribution in focal plane

The structure of a binary phase diffractive axicon is determined by grating's fill factor, stripes position within period and a phase difference value. Earlier an analysis of fill factor influence was fulfilled, and it was shown that an expansion of the grating transmittance function to Fourier series is effective approach. The stripe shift influence is investigated using this approach. It was proved that the shift is equivalent to a fill factor change but it is more effective because we are able to fix equal stripes width that ensures a small value of zero order. Results of theoretical and numerical calculations agree with each other. Таким образом, возможно динамическое изменение вида фокального распределения за счёт сдвига полос в периоде. As a result, there is the ability to dynamically change the focal structure due to regulation of the stripes position by means of a spatial light modulator.