Pyrometer process temperature measurement for high power light sources

A material processing system comprising:

• a high power laser source situated to emit a non-pyrometer material processing beam having an output power of at least 30 W so as to process material at a work surface;
• a pyrometer situated to receive a pyrometer measurement signal from the work surface and to measure at least one parameter of the material at the work surface;
• a pyrometer pickoff configured to receive the material processing beam and the pyrometer measurement signal and to direct the pyrometer measurement signal to said pyrometer;
• a homogenizing delivery waveguide having first and second opposite ends, said delivery waveguide optically coupled at a first end to said pyrometer pickoff and configured to counter-propagate the material processing beam and the pyrometer measurement signal;
• and
• a process optic optically coupled to said second end of said delivery waveguide and configured to receive the material processing beam from said second end of said delivery waveguide and direct the material processing beam to the work surface and configured to receive the pyrometer measurement signal from the work surface and to direct the pyrometer measurement signal to said second end of said delivery waveguide;
• wherein a spot of the pyrometer measurement signal at the work surface and received by the pyrometer is aligned with a spot of material processing beam at the work surface by the counter-propagation of the pyrometer measurement signal and the material processing beam through said delivery waveguide.

A method of measuring a parameter of a work surface, comprising:

• providing a homogenizing optical delivery waveguide in optical communication with the work surface;
• propagating a non-pyrometric material processing beam, having a power of at least 30 W and generated from a high power laser source, through the optical delivery waveguide to the work surface so as to process the work surface;
• and
• propagating a pyrometer measurement signal through the optical delivery waveguide in the reverse direction of the material processing beam to an optical pyrometer wherein a spot of the pyrometer measurement signal at the work surface received by the optical pyrometer is substantially the same as a spot of the material processing beam at the work surface.