Diffuse Reflectance Measurements from Different Surfaces

Relative diffuse reflection measurements from the original and ground surfaces using a He-Ne laser are reported. The intensity measurements for the metallic, transparent dielectric, matte plastic surfaces and colored papers are presented. Our results indicate that among metallic surfaces tested, aluminum has the highest diffuse reflectance; while the original stainless steel surface shows the lowest. The primary result is that for the ground metallic surfaces, there seems to be an optimum condition and roughness that result in the maximum diffuse reflection. For the color matte plastics, the yellow color has the highest diffuse reflectance and the black one shows the lowest. For the colored papers the yellow paint shows a maximum diffuse reflectance; whereas the gray one has the lowest diffuse reflectance. Our results agree with the theoretical predictions and also with the other experimental results. * E-mail: [email protected] Introduction When a ray of light strikes the surface of an object, it may be absorbed, transmitted, or reflected. Considerable attention has been paid to reflectance study of various surfaces. Some studies have concentrated on the experimental determination of surface reflectance, and at the same time, many theories have been developed for surface reflection modeling [1]. Two limiting cases were considered at the early stages: the light reflected in a particular direction (perfect specular), or the light reflected in all directions of a hemisphere above the surface uniformly (Lambertian). These two ideal cases for a surface are never attained in practice, and it is advisable to consider both effects to describe the reflection properties of a surface.