1. LIGHT WAVES

2. Light is an electromagnetic wave.
Its motion is transverse.
Light travels in straight lines.

3. Visible light- the set of light wavelengths that stimulate the retina of the eye.
ROY-G-BIV

4. VISIBLE LIGHT RANGE: Wavelength: 400nm – 700nm (1nm= 1x10-9m)
4x10-7m – 7x10-7m

5. SPEED OF LIGHT:
c = 3 X 108m/s
This is the same for all electromagnetic waves!!!!

6. AS WAVE LENGTH INCREASES, FREQUENCY DECREASES.
V = fλ where v is always the speed of light.
f (Hz)
λ (m)

7. ELECTROMAGNETIC SPECTRUM

8. Infrared rays- frequency is lower than visible light
Infrared rays- frequency is lower than visible light. Responsible for heating the earths atmosphere.(less then 4.3x1014Hz)
Ultraviolet rays- frequency higher than visible light. Responsible for skin cancer. (greater than 7x1014Hz)

9. Infrared ROY-G-BIV ultraviolet
Low frequency High frequency
Infrared ROY-G-BIV ultraviolet
High λ Low λ
Low energy high energy
velocity is always 3x108m/s velocity is always 3x108m/s velocity is always 3x108m/s

10. TERMS
Luminous- a body that emits its own light.

11. Illuminated- Body that reflects light.

12. Transparent- a medium that allows light to travel through it.

13. Translucent- distorts light.

14. Opaque- reflects or absorbs light.

15. PHOTOMETRY
The study and measurement of visible light in terms of its perceived brightness to human vision.

16. SOURCES OF LIGHT
Incandescent light- object gives off light when heated.

17. Neon Light – Light produced when electrons in a tube of gas are excited.

18. Fluorescent light- Ultraviolet rays strike a white powder coating on the inside of the bulb causing it to glow.

19. Black light- High frequency visible light (purple) which can cause other objects to fluoresce or glow.

20. LED- light emitting diode

21. Laser light- Light amplification by stimulated emission of radiation

22. Laser light is monochromatic (one color) and coherent (in phase)
Laser light is monochromatic (one color) and coherent (in phase). This produces a small beam instead of scattered light

23. Rhodamine 6G dye (tunable)
Laser Type
Wavelength (nm)
Argon fluoride (UV)
193
Krypton fluoride (UV)
248
Xenon chloride (UV)
308
Nitrogen (UV)
337
Argon (blue)
488
Argon (green)
514
Helium neon (green)
543
Helium neon (red)
633
Rhodamine 6G dye (tunable)
Ruby (CrAlO3) (red)
694
Nd:Yag (NIR)
1064
Carbon dioxide (FIR)
10600

24. USES FOR LASERS 1) Medical Field Correcting vision surgery
Correcting skin imperfections
2) Electronics:
CD and DVD players ( and blue ray discs)
Supermarket Scanners
Laser light shows
3) Fiber optics: computers, internet, phones, cable TV- for transferring information and data.
4) Industry: Cutting, blasting, and welding
USES FOR LASERS