Abstract: In some implementations, a method comprises: determining a set of characteristics of light spectra reflected or transmitted by a set of materials when the set of materials is illuminated by a plurality of light wavelengths; constructing one or more classifiers configured to classify each material of the set of materials based on the set of characteristics of the light spectra; using the classifiers, mapping each of the light spectra onto an area of an image sensor; wherein one or more optical elements filter and focus the light spectra onto one or more elements of a detector array; wherein each optical element focuses onto an area of the detector array; wherein the mapping is a 1:1 mapping; wherein each optical element uses a Bragg reflection condition to filter the light spectra and to focus the light spectra onto an element of the detector array.

Abstract: In some implementations, a method for authenticating and classifying a set of materials comprises: transmitting a visible range light from a light source toward a vessel containing a material sample; wherein the visible range light passes through the vessel containing the material sample, passes through the material sample, and bounces off a HOE located at a bottom of the vessel toward a camera implemented in a smartphone; receiving, by the camera of the smartphone, the visible range light that bounced off the HOE; based on a mapping of each of the visible range light onto an area of an image sensor, generating a holographic optical element that has a plurality of regions, that receives input light reflected or transmitted through a new material, and that filters the input light to a filtered light by each characteristic light spectra, and mapping the filtered light onto the image sensor's area.