An optical physiological sensor configured to perform high speed spectral sweep analysis of sample tissue being measured to non-invasively predict an analyte level of a patient. An emitter of the optical physiological sensor can be regulated to operate at different temperatures to emit radiation at different wavelengths. Variation in emitter drive current, duty cycle, and forward voltage can also be used to cause the emitter to emit a range of wavelengths. Informative spectral data can be obtained during the sweeping of specific wavelength regions of sample tissue.