1. SCPY152 General Physics II Lecture 1 Ray Optics
Udom Robkob, Physics-MUSC
June 15, 2015

2. Today Topics Nature of light Light rays Law of light reflection
Law of light refraction
Image formation
Images from mirrors
Images from refractive surfaces

3. Nature of Light
Visible light is electromagnetic waves, in the range of wavelength 400 – 700 nm
Light travel in empty space at speed of co = 3x108 m/s
In medium light speed is lower to be c, according to electromagnetic properties of the medium. The ratio co/c = n is known as refractive index of the medium

4. Nature of Light

5. Nature of Light
4 basic properties will be studied in the following categories:
Reflection and refraction  ray optics
Interference and diffraction  wave optics

6. Light Rays Defined from light path from the source
At a distance far from the source, the rays are approximately parallel and will represented with a single ray

7. Light Reflection
Determine reflection of light from smooth reflective surface;

8. Light Reflection
Since abc = abd  1 = ’1 “law of light reflection”

9. Light Reflection
Double reflections

10. Light Refraction
Determine light refraction at smooth refractive surface

11. Light Refraction
Law of light refraction

12. Light Refraction
Nature of refraction

13. Light Refraction
Off set from thin slab

14. Light Refraction
Measuring refractive index of prism, apex angle is 

15. Light Refraction
Criterion:  min

16. Critical Angle Total internal reflection – critical angle
Water-to –air system

17. Brewster’s Angle
Brewster’s angle

18. Image Formation
Pinhole camera

19. Images from Mirrors
Mirror specification (let light comes from the left hand side)
Plane mirror
Curved mirrors
Concave mirror
Convex mirror

20. Images from Mirrors
Image of point object

21. Images from Mirrors
Image magnification
Mirror image equation

22. Images from Mirrors Image magnification Focal point/length
Mirror image equation

23. Images from Mirrors

24. Images from Mirrors

25. Images from Mirrors

26. Images from Refractive Surface
Refractive surfaces
Convex surface
Concave surface

27. Images from Refractive Surface
Image of point object

28. Images from Refractive Surface
Cont.
Image equation

29. Images from Refractive Surface
Flat refractive surface – appearing depth

30. Images from Refractive Surface
Concave refractive surface – appearing depth

31. Images from Refractive Surface
Image magnification – from equivalent triangles, we have

32. Images from Refractive Surface
Revisited previous example – what is the image magnification of the coin.