Temperature measurement and control for photohermal processes

Abstract

The temperature of a surface undergoing a radiation assisted thermally driven process is sensed by observation of the thermal emission from that surface and used to control the process. In a preferred embodiment, the blue edge of the thermal emission spectral distribution is detected to determine the surface temperature of a workpiece during a process such as laser-assisted chemical vapor deposition, and used to control this temperature. The temperature measuring system has means for focusing workpiece thermal emission and defining the field of view, a spectrometer to separate shorter wavelength light from other spectral components of the thermal emission, and a photon-counting system to detect the shorter wavelength light and generate a surface temperature signal. Systems to determine surface temperature at a spot and along a line have an optical prism to disperse the thermal emission into component wavelengths, and a multichannel photon-counting detector comprised of an intensified photodetector array.

Dependencies are inferred from the claim text.