A tissue analyte measuring device (2) includes a light source (4) structured to emit unpolarized light toward the skin surface of a subject, and a detector assembly (8) configured to receive light reflected from the skin surface of the subject and the transcutaneous tissues of the subject, the detector assembly including a polarizing filter (12) and a number of light detector subassemblies (14). The polarizing filter is structured to filter out s-polarized light and pass only p-polarized light to light detector subassemblies. The light source is structured and positioned to emit the unpolarized light in a manner wherein the unpolarized light will exit the measuring device at a predetermined angle with respect to a normal to a light emitting plane of the measuring device, wherein the predetermined angle is an angle (the Brewster's angle) at which only s-polarized light will be reflected by the skin surface when the unpolarized light is incident thereon.