Noncontact temperature measurement by double-wavelength shift of Brewster angle

摘要

Embodiments disclosed herein relate to a thermal processing chamber having a substrate monitoring system. In one embodiment, a temperature monitoring system is disclosed herein. The temperature monitoring system includes a window and a housing defining an internal volume. The temperature monitoring system further includes two or more light sources, a camera, and a polarizer. Two or more light sources are placed under the window, in the internal volume. A first one of the two or more light sources has a first wavelength. And the second one of the two or more light sources has a second wavelength. A camera is placed facing two or more light sources. The camera is configured to capture a plurality of frames of two or more light beams from two or more light sources. The polarizer is disposed in the optical path of two or more light beams.