Designing method of vortex beam mask with oblique-line compressed phase step

[0033] Taking a mask with a size of 512×512 as an example, a vortex beam mask with obliquely compressed phase steps is given for a laser with a working wavelength of 532nm. The value of the topological charge of the mask is m=5, the slope of the compressed slope K=0.2~0.5, and the value of the first phase step is a 1=1.019π, according to the transmittance function of the mask in the specific embodiment, a vortex beam mask with oblique line compressed phase steps is finally obtained. figure 1 The vortex beam mask for the obliquely compressed phase step is given. This vortex beam mask with obliquely compressed phase steps can be realized by a spatial light modulator. Take the PLUTO-VIS-016 phase spatial light modulator of German Holoeye Company as an example, its pixel size is 8 μm, the fill factor is 93%, and the resolution is 1920pixel×1080pixel. A continuous wave solid-state laser with a wavelength of 532nm and a power of 100mW was used in the experiment.

[0034] figure 2