Measured radiation spectra of the W-PC sample heated to T = 575K. The data were taken for a series of aperture positions, from pos. −0 to pos. −5. At Pos. −0, the aperture is aligned with the black-CNT area and the emission shows a smooth λ-dependence. At pos. −1, the aperture is moved away from the CNT area and into the PC-cavity area, a small emission peak occurs at λ = 1.7 μm. As the aperture is moved from pos. −2 to pos. −4, the emission peak at λ = 1.7 μm becomes more distinct. At pos. −5, when the aperture is completely out of the CNT area and aligned only with the W-PC area, the peak intensity reaches its maximum. This peak intensity is 8.3 times above the blackbody reference taken at pos. −0.