Generation of optical vortex array by using a diffraction grating

The generation of an optical vortex array (OVA) by using diffraction grating is presented. At first a diffraction grating is produced with a computer and displayed on a spatial light modulator (SLM) which is controlled by the computer. Then let a plane light irradiate the SLM with the diffraction grating vertically. The transmitted lights after the SLM can produce a regular optical vortex array which can be observed by adjusting the diffraction distance of the grating. The principle of the generation is discussed and the distribution of the intensity of the optical vortex array is presented. The properties of the produced optical vortex array at different diffraction distance are also discussed. The simulations are completed and the results show that the optical vortex array can be generated well by using the diffraction grating, which is simple and easy to implement. And we measure the deformation phase by using the zero-contour of the real parts of the OVA, which provides a new method for deformation phase measurement.