A light-emitting module for use in a system for measuring whole-blood hemoglobin parameters or whole-blood bilirubin parameters. The light-emitting module includes an LED light source capable of emitting light wherein the light is directed thereby defining an optical path and a plurality of optical components. The plurality of optical components includes a collimating lens, a first optical diffuser, a circular polarizer, and a focusing lens wherein the plurality of optical components is disposed within the optical path of the light from the LED light source.