Final answer:
Enhancing the visibility of a specular reflector, like a CD, involves analyzing the diffraction pattern created when it reflects light. By examining the distance from the central fringe to the first-order fringe, and the distance from CD to the wall, we can calculate the spacing of grooves on the CD using the principles of light diffraction.
Step-by-step explanation:
To enhance the visibility of a specular reflector, certain conditions have to be met. When a laser beam is reflected from the surface, as in the case of a He-Ne laser beam reflected from the surface of a Compact Disc (CD) onto a wall, creating fringes of light, certain geometric relationships allow us to determine features such as the spacing of grooves on a CD. Assuming the bright central fringe corresponds to a zeroth-order maximum, we can use Bragg's law, which relates the wavelength of the light, the angle of incidence, and the spacing between the grooves of the CD to calculate the groove spacing. Given the distances to the wall and to the first-order fringe, we can set up a right triangle and use the small angle approximation to find the angle of the first-order fringe, from which we can solve for the spacing using a form of Bragg's Law specific to the geometry of a CD's reflective surface.