Ch 23 vocab

  1. Ray model
    A model that assumes light travels in rays
  2. Ray
    Straight-line path
  3. Geometric optics
    The subject of light acting as a ray with reflection, refraction, and the formation of images by mirrors and lenses
  4. Angle of incidence
    The angle an incident ray makes with the normal (perpendicular) to the surface
  5. Angle of reflection
    The angle the reflected ray makes with the normal
  6. Law of reflection
    The angle of reflection equals the angle of incidence
  7. Diffuse reflection
    When light hits a rough surface and is reflected in many directions
  8. Specular reflection
    When light hits a smooth surface and reflects in one direction
  9. Image
    Picture made by reflected light
  10. Virtual image
    An optical image formed by the apparent divergence of rays from a point, rather than their actual divergence from a point (when it doesn't actually focus, but our brain connects the dots)
  11. Real image
    An optical image formed by the actual divergence of rays from a point (never upright - opposite of virtual)
  12. Convex
    Spherical mirror with which the reflection takes place on the outer surface so that the center of the mirror surface bulges out
  13. Concave
    A mirror where the reflecting surface is on the inner surface so that the center shrinks away (like a cave)
  14. Focus
    Where reflected parallel rays cross each other
  15. Principal axis
    The straight line perpendicular to the curved surface at it's center
  16. Focal point
    • Where incident parallel rays come to a focus after reflection
    • Also the image point for an object infinitely far away along the principal axis
  17. Focal length
    Distance between the focal point and the center of the mirror
  18. Paraxial rays
    Rays that make a small angle with the principal axis, so that they reflect at F
  19. Spherical abberation
    When rays from an image pass through the outer regions of the lens or mirror and are brought to a focus at a different point from those that pass through the center of the lens.
  20. Do
    Object distance, distance of the object from the center of the mirror (x value)
  21. Di
    Image distance, distance of the image from the center of the mirror (x value)
  22. Ho
    Object height, height of the object from the center of the mirror (y value)
  23. Hi
    Image height, height of the image from the center of the mirror (y value)
  24. Mirror equation
    • 1/do + 1/di = 1/f
    • Where f is the focus, or r/2.
  25. Magnification
    "m", the height of the image divided by the hight of the object (hi/ho). This is also (-di/do).
  26. Index of refraction
    The ratio of the speed of light in a vacuum to the speed v in a given material. Denoted as n.
  27. Refraction
    When a ray of light changes direction as it enters a new medium
  28. Angle of refraction
    The angle the refracted ray makes with the normal to the surface
  29. Snell's law
    The angle of refraction depends on the speed of light in the two media and on the incident angle, also written as n[1]sint[1] = n[2]sint[2].
  30. Law of refraction
    Snell's law, or n[1]sint[1] = n[2]sint[2]
  31. Critical angle
    The incident angle at which the refracted ray would skim the surface, meaning the angle of refraction would be 90 degrees.
  32. Total internal reflection
    • When there is no refracted ray, all of the light is reflected
    • Only occurs when the second medium has a lower index of refraction
  33. Fiber optics
    Total internal reflection used with tiny fibers as thin as a few micrometers in diameter
  34. Converging lens
    A lens that is thicker in the center than at the edges, which will make parallel rays converge to a point
  35. Diverging lens
    A lens that is thinner in the center than at the edges, and make parallel light diverge
  36. Thin lens equation
    Same as the mirror equation, 1/do = 1/di = 1/f
  37. Sign conventions
    • Focal length: pos for converging, neg for diverging
    • Di: pos if image is on opposite side of the lens, neg if same side
    • Hi: pos if upright, neg if inverted
Author
megame623
ID
152338
Card Set
Ch 23 vocab
Description
Ch 23, geometric optics
Updated