Optics The Study of Light Areas of Optics Geometric Optics Light as a ray. Physical Optics Light as a wave. Quantum Optics Light as a particle.
Post on 18-Dec-2015
244 Views
Preview:
Transcript
Areas of Optics
Geometric OpticsLight as a ray.
Physical OpticsLight as a wave.
Quantum OpticsLight as a particle.
Optical images• Nature
• real (converging rays)• virtual (diverging rays)
• Orientation• upright• inverted
• Size• true• enlarged• reduced
Spherical mirrors
shiny shiny
concave convex
+ + --(where reflected rays go) (where reflected rays go) (dark side)(dark side)
Focal length, f, is positive Focal length, f, is negative
Mirror equation # 2• M = -si/so = hi/ho
• si: image distance• so: object distance• hi: image height• ho: object height• M: magnification
Concave vs convex mirrors Concave
Image is real when object is outside focus
Image is virtual when object is inside focus
Focal length f is positive
Convex Image is always
virtual
Focal length f is negative
Real vs Virtual images Real
Formed by converging light rays
si is positive when calculated with mirror equation
Virtual Formed by
diverging light rays
si is negative when calculated with mirror equation
Upright vs Inverted images Upright
Always virtual if formed by one mirror or lens
hi is positive when calculated with mirror/lens equation
Inverted Always real if
formed by one mirror or lens
hi is negative when calculated with mirror/lens equation
Definition: Refraction
Change in speed of light as it moves from one medium to another.
Can cause bending of the light at the interface between media.
Dispersion
The separation of white light into colors due to different refractive indices for different wavelengths.
Critical Angle of Incidence
n1
n2
c
Light would refract 90o so it reflects instead, undergoing total internal reflection.
r
n1 > n2
Announcements 04/18/23
Turn in homework (lens problems) on overhead.
Lab report will be due next week (on looseleaf or graph paper).
Consider a lens with f = 20 cm.
You place a 5 cm tall object 30 cm in front of the lens.
a)Draw the ray diagram and construct the image.
b)Calculate the image distance and height using the lens/mirror equations.
c)Name the image.
For converging lenses
• f is positive• so is positive• si is positive for real images and
negative for virtual images• M is negative for real images
and positive for virtual images • hi is negative for real images
and positive for virtual images
top related