Patent ID: 7789556

Claim:
A method for determining the surface temperature of a sample, the method comprising: positioning a fiberoptic temperature sensor in proximity to a sample, the fiberoptic temperature sensor comprising a first probe having a first phosphor tip offset from a second probe having a second phosphor tip by a fixed separation distance, such that the first phosphor tip is at a first distance from the sample and the second phosphor is at a second distance from the sample which is equal to the first distance plus the fixed separation distance; heating each of the probe tips to the same plurality of temperature levels by subjecting the phosphor tips to a plurality of predetermined laser power levels with the probe tips positioned in proximity to the sample surface; measuring the temperature of each of the phosphor tips substantially simultaneously at each of the plurality of laser power levels with the tips positioned in proximity to the sample surface; calculating the difference between the measured temperatures of the first phosphor tip and the measured temperatures of the second phosphor tip for each of the plurality of laser power levels; and determining the surface temperature of the sample to be the temperature of the phosphor tip when the difference between the measured temperature of the first phosphor tip and the measured temperature of the second phosphor tip is substantially equal to zero.