OP MT2
Card Set Information
Author:
Alicat38
ID:
116527
Filename:
OP MT2
Updated:
2011-11-14 22:48:55
Tags:
definitions
Folders:
Description:
Op
Show Answers:
Curvature of surface
the angle turned through per unit length of arc
R = 1/r in Dioptre (D)
Refraction
Light passes through an interface b/t 2 optical media
Reflection
Light bounces at interface
Image
New wavefront curvature (vergence in air) L' gives distance to image
More curvature ->
more vergence changing power
Lens gauge/clock/measure
measures surface power by measuring the sag of a lens of a specific refrative index
Centered or symmetrcal elements
elements positioned such that they have a common axis
Surface power
Measure of the ability of the surface to change the vergence of light
Fs = (n'-n)/r = n'/f' = -n/f
in Dioptre
Chief ray of extended object through a spherical surface
ray passes through the center of curvature (it is undeviated because it is normal to the spherical surface)
Lens
has two refracting surfaces (both surfaces spherical or one surface may be plano (plane, no curvature, zero power))
Center thickness
Thickness at the vertex of the lens
Thin lens
negligible centre thickness, change in vergence as light passes through the lens is insignificant
Biconvex/concave
both surfaces are have the same sign but different powers
Equiconvex/concave
both surfaces have the same power
Meniscus
center of curvature is on the same side of lens for both surfaces
planoconvex/concave
zero power on one side, all power on other side
Lens form (bending)
any power of lens can be obtained by a combination of surface powers
Principal foci
Light from infinity (parallel) passes lens and focuses at the SECOND prinicipal focus
Light emerging from FIRST principal focus emerges from the lens parallel
Symmetric planes
closest possible distance b/t a real object and its real image in a plus lens
OR
closest possible distance b/t a virtual object and its virtual image in a minus lens
Principal plane
location of object and image when m=+1