The alternative "textbook" electromagnetism answer is to use the boundary condition for the electric field either side of an interface - this is that the component of electric field parallel to the interface (i.e. Any optics textbook should have the calculation, or a quick Google found an example here. This is basically the Huygen's construction, and if you do the sums for a surface you can show that the overall scattering is only non-zero when the angle of reflection is equal to the angle of incidence. Add lots more to make a 2D surface, then add more layers of silver atoms below, and you're building up a system where the overall light scattering is the sum of individual scattering from huge numbers of individual silver atoms. Now add lots of atoms in a row, and you get something like a diffraction grating. (I'm oversimplifying because two atoms would be too closely spaced to act as Young's slits, but bear with me.) Now the light isn't simply isotropically scattered, but instead it's scattered into preferred directions. Each atom will scatter isotropically, so in effect we have two closely spaced emitters of light and the system behaves like a Young's slits setup. it will scatter the light equally in all directions.īut suppose we have two silver atoms side by side. The starting point it that a single silver atom is far smaller than the wavelength of light, so any scattering from it will be isotropic i.e. Without realising it you have stumbled across the Huygens-Fresnel principle. When the ray of light passes through the center of curvature, after reflection it travels along the same path.That's a good question. When the ray of light passes through the principal focus of the mirror, after reflection it travels parallel to the principal axis. When the ray of light strikes at the pole of the mirror, after reflection the reflected ray makes the same angle as the incident ray. When the ray of light is traveling parallel to the principal axis, after reflection the ray of light diverges from the mirror. The reflection that occurs in a convex mirror is different from the concave mirror. Because of this, the image forms on the opposite side of the mirror. The convex mirror diverges the rays of light after reflection. Just like the concave mirror, the center of the convex mirror is also known as the pole. When the ray of light passes through the center of curvature, after reflection it travels along the same path.Ī convex mirror is another type of spherical mirror with a reflecting surface thatĬurves outwards. When the light ray passes through the focus and strikes the mirror surface, after reflection the reflected ray travels parallel to the principal axis. When a ray of light strikes the center of the mirror, after reflection the reflected ray makes the same angle as the incident ray. If a light ray travels parallel to the axis of the mirror, then after reflection the reflected ray passes through a point known as a focus. The reflection of the light ray also depends on the path of the light before reflection. Due to theĬurved surface of the mirror, each ray of light striking the surface reflects differently. The concave mirror converges the rays of light after reflection. The concave mirror can form a magnified or diminished image depending on the position of the image.
The reflection in the concave mirror is different from the plane mirror. The image formed by the spherical mirror differs in size.Ī concave mirror is a spherical mirror whose reflecting surface curves inwards. Spherical mirrors are another type of mirror that reflects light.
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