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  • Quiz
  • Types of Reflections

    Specular vs Diffuse Reflections

    Specular reflections are mirror-like reflections and can reflect close to 100% of the incident light.

    Flat surfaces will not change a fixed beam diameter only the direction (Figure 13).

    Convex surfaces will cause beam spreading, conversely concave surfaces will make the beam converge (Figure13).

    Diffuse reflections (Figure 14) result when surface irregularities scatter light in all directions. The specular nature of a surface is dependent upon the wavelength of incident radiation. A specular surface is one that has a surface roughness less than the wavelength of the incident light. i.e. A very rough surface is not specular to visible light but might be to IR radiation of 10.6 um from a CO2 laser.

     

    Figure 13 - Specular Reflection

    Figure 14 - Diffuse Reflection

    specular reflection

    diffuse reflection