MEASURING APPARATUS OF LIGHT INTENSITY

摘要

PURPOSE:To obtain an apparatus which measures accurately the absorption coefficient of a semiconductor wafer for an infrared light and also can measure photoluminescence at the same position. CONSTITUTION:A transmission-type sample holder 11 is disposed on an optical path between a light source 1 and an infrared detector 17. The holder 11 is so provided that it can be rotated by an automatic rotary stage 12 around the axis intersecting the optical axis perpendicularly. A sample being tilted at a Brewster angle, an infrared light is applied thereto and the light transmitted therethrough is measured by the infrared detector 17. The holder 11 being made erect on the optical axis, besides, a laser light is applied onto the surface of the sample from a laser light applying device 21 and the intensity of an excited light thereof is measured by the infrared detector 17 through a spectroscope 16. Absorption and luminescence are measured in regard to the same position of the sample.