A chemical imaging and process monitoring device which utilizes a computer controlled tunable laser to provide light at discrete wavelengths in the near infrared band and a focal plane array to image or a single-point photo detector to detect the intensity of light reflected from a sample illuminated at various wavelengths of light. The device also provides light intensity reference detectors at the source and terminus of the light delivery pathway for normalizing the collected data and for detecting defects in the light delivery pathway.