Thin Black Screens for Diffraction Measurements

Black paints covered with multidielectrics: light absorbers

“…Light absorbers are commonly required to cancel or reduce parasitic light in optical systems [1][2][3][4][5][6][7][8][9][10][11][12]. In the field of high precision optics (of which micro-multiplexing devices and multiple channel micro-sensors are examples) their specifications have become severe since they are a major limitation to the isolation rates between communication or imaging channels.…”

“…Different techniques [1][2][3][4][5][6][7][8][9][10][11][12] can be used to produce such devices, and surely the most classical is to coat a smooth (polished) absorbing substrate with dielectric anti-reflective layers. In this case the design of the multidielectric coating can be optimized and drives the absorber performance.…”

“…As an alternative solution, black paints have also provided great help in the production of light absorbers [1,2,4,19,20]. The process is different in the sense that specular reflection is replaced by diffuse reflectance with a quasi-lambertian scattering, due to high substrate roughness and short correlation length.…”