Research on the Aperture Area Measurement based on Optical Flux Comparison Method

Accurate measurement of the aperture area has always been the focus of optics and optical radiation measurement. The metrology institutes around the world have established absolute aperture area measurement facilities. In this paper, a measuring system of the aperture area based on optical flux comparison method is designed and implemented., which can transfer absolute values efficiently and accurately. The results show that the deviation between the area measured by optical flux comparison method and the area measured by effective area method is about 5 x 10(-4). The influences of the light source stability, irradiation field uniformity and aperture positioning difference on the measurement results are analyzed emphatically. The uncertainty of the measurement results is also evaluated, the relative expanded uncertainty is 9.9 x 10(-4)(k=2).