Abstract: The present invention discloses a pattern projector based on VCSEL array. The VCSEL array has a plurality of VCSELs configured in a regular pattern on a VCSEL chip. A certain number but not all of the VCSELs are selected for two groups. In one operational mode, VCSELs of one group are powered on to form a low-density irregular pattern. A lens system projects an image of the low-density irregular pattern on a diffractive optical element (DOE). The DOE multiplies a replica of the image and generates a matrix of the replicas on a target surface. In another operational mode, VCSELs of the two groups are powered on simultaneously or the second group is powered on alone to form a high-density irregular pattern. An image of the high-density irregular pattern is projected on the DOE. Thus, the pattern projector may provide irregular light patterns for low-resolution and high-resolution 3D sensing.

Abstract: Nuclear magnetic resonance (NMR) simulations of a porous medium are provided based on physical data such as CT images. A method of evaluating the surface relaxation of the porous medium based on random-walk NMR simulations includes a novel algorithm to derive the absorption probabilities of the random walkers, and algorithms that can evaluate more accurately the surface area and reduce the voxel discretization effect. The methods can be applied to conventional porous media as well as unconventional porous media such as reservoir rocks with high surface-to-volume ratios, for example tight sandstones or shale.

Abstract: Nuclear magnetic resonance (NMR) simulations of a porous medium are provided based on physical data such as CT images. A method of evaluating the surface relaxation of the porous medium based on random-walk NMR simulations includes a novel algorithm to derive the absorption probabilities of the random walkers, and algorithms that can evaluate more accurately the surface area and reduce the voxel discretization effect. The methods can be applied to conventional porous media as well as unconventional porous media such as reservoir rocks with high surface-to-volume ratios, for example tight sandstones or shale.