Enhanced infrared normal spectral emissivity of plane blackbody radiation source using a femtosecond laser micromachining method

摘要

As a thermal reference source, plane blackbody radiation source is widely used in infrared instrument calibration. In practical application, it is required that the normal spectral emittance of the plane blackbody radiation source should be greater than 0.95. However, the plane blackbody radiation source made by traditional sand blasting process cannot meet the requirement. Here we demonstrate a new manufacturing process for the plane blackbody radiation source. We selected aluminum material with a thickness of 10mm as the substrate, and then we roughed the substrate surface by femtosecond laser micromachining. Next, we sprayed on the prepared surface with heat resistant coatings and finished the manufacturing process. In comparison, we also made the plane blackbody radiation source by the sand blasting process with the same substrate and heat resistant coatings. Compared with the samples treated by sand blasting, we find that the samples treated by femtosecond laser show much smoother spectral emittance curves and higher spectral emissivity, and the average spectral emissivity is higher than 0.95 from 8μm to 18μm at the temperature of 500 °C. Our results suggest that femtosecond laser micromachining is an effective way to obtain high quality plane blackbody radiation source.