1. A detection system, comprising: a transmitter configured to transmit electromagnetic energy at two or more wavelengths, wherein the electromagnetic energy has a selected polarization state; a receiver configured to receive scattered electromagnetic energy that has been scattered by a material illuminated by the transmitted electromagnetic energy, and measure the received polarization states at the two or more wavelengths and total backscatter intensity at the two or more wavelengths; a processor configured to combine the measured polarization states at the two or more wavelengths and the total backscatter intensity at the two or more wavelengths into a plurality of different combinations to obtain input parameters, wherein each combination comprises the power of one of the polarization states at one of the wavelengths divided by the power of the total backscatter intensity across the two or more wavelengths, and to classify the material illuminated by the transmitted electromagnetic energy based on the input parameters.