1. Optical Devices
Is any device that creates, manipulates or measures electromagnetic radiation.

2. Electromagnetic Spectrum

3. Gama ray
Gama rays are the shortest in wavelength. Smaller than nanometers (the size of an atomic nucleus). These are the highest energy (high frequency) part of the electromagnetic spectrum. These occur from nuclear reactions.
These rays can be used to sterilize hospital equipment.
Gama rays are used in radiation therapy. It kills cancerous cells but it can also kill normal cells. Gama rays at low dozes can also create cancerous cells, therefore precautions need to be taken when these rays are used in radiation therapy.
Gama rays are stopped by lead.

4. Gama Ray Observatories
Gama ray burst can occur from stars collapsing, black holes…etc.
“Gamma-ray bursts can release more energy in 10 seconds than the Sun will emit in its entire 10 billion-year lifetime”

5. X-ray
X-ray waves are produced in space sometimes by black holes eating up gas from nearby stars. These waves do not reach our atmosphere. These wavelengths range in size from nanometers (the size of an atom).
To be able to study theses x-rays we need high altitude satellites the Yohkoh X-Ray Telescope, to study X-ray light in space. Yohkoh x-ray telescope only
Used in radiation therapy at a lower frequency

6. X-ray
X-rays pass through skin and soft tissue. They do not pass through bone or metal. Low dozes of X-ray can cause cancer. That’s why there are limits to the number of X-rays you can have per year. When you get an X-ray done, you wear a lead vest or covering over the other parts of your body to prevent exposure to those areas.

7. CT Vs. MRI X-ray CT scan uses X-ray MRI uses magnetic field
CT scan vs Mri
CT scan uses X-ray
MRI uses magnetic field
soft tissue in ligament and tendon injuries, spinal cord injuries, brain tumors, soft tissue in ligament and tendon injuries, spinal cord injuries, brain tumors,
bone injuries, diagnosing lung and chest problems, and detecting cancers

8. Radiation Therapy Masks
X-ray
Radiation Therapy Masks
Radiation therapy masks contribute to 80-90% cure of some cancers.
To read more about radiation therapy masks

9. Ultraviolet
Only a small portion of the sun’s ultraviolet light reaches the ground. This is due to the Ozone layer in the atmosphere. These are very short wavelength nm (the size of a molecule)
Why do we get sunburned? Ultraviolet light is absorbed by our skin and interacts with molecules, destroying them.
How can we prevent getting sunburned?
Use this in tanning. Ultraviolet is important to us as it promotes the production of vitamin D. Too much can be very harmful, from causing premature aging to causing melanoma (skin cancer)
Ultraviolet light aids in photosynteiss in plants.

10. Ultraviolet
Tanning

11. Ultraviolet

12. “How the sun sees you” video
Ultraviolet
Darker skin absorbs ultraviolet light so less ultraviolet radiation reaches into the deeper tissue.
“How the sun sees you” video

13. Detecting Fake Banknotes
Ultraviolet
Detecting Fake Banknotes
Banks will have invisible features on bank notes. These features will fluoresce (glow) under uv light.

14. Visible
The wavelength are from 0.35 to 0.9 micrometer (the size of a bacteria). We sense these wavelength as color.

15. Visible
Colours

16. Infrared Micrometer length
Remote control uses infrared light at a certain peak to allow you to change the channel
We emit infrared heat at a different peak. Recall: Snakes see both in regular vision (like we do) and in infrared.
Infrared radiation can be felt as heat. This is used in toasters and grills. Infrared is also used in optical fibers.

17. Infrared
How fiber optics works: light traveling through a very pure glass. The light reflects off the sides of the glass in total-internal reflection. We witnessed total internal reflection with the weights/coins and water station.

18. Fibre optics in medicine
Infrared
Fibre optics in medicine

19. Infrared
Endoscopes
Fibre optics used to transmit pictures of organs, tissues, arterires,…. Etc.

20. Infrared
Neat
nemen LED jacket weaves optical fibers within nylon and steel fabric. This jacket costs about 3,000 dollars. The high price is due to the number of man hours and patience it took to make. The battery lasts up to 8 hours.

21. Infrared lamps Infrared
Infrared lamps produce heat that can be used in therapeutic means or to heat food. Infrared lamps can also be used to help dry paint.

22. Infrared
Insulation

23. Infrared
Diagnostic imaging

24. Infrared
Diagnostic imaging

25. Infrared
Diagnostic imaging

26. Microwaves
Microwaves are reflected by metal. They are absorbed by water in food. Microwaves cause the water to heat up which then cooks your food. Water is also in your cells, which means that your cells will be damaged if water absorbs microwaves. Remember to stand away from the microwave when it is in use.
Another use for microwaves is telephone satellite. When you use the phone, your voice is translated into microwaves

27. Interesting findings Microwaves
For this science fair experiment. Two plants received purified water that was heated first then let stand to cool. One plant used water heated by the microwave and the other was heated by the stove. From the results, it appears that the water molecules have been altered.
If you want to read more about this:

28. Microwaves

29. Microwaves
Ridiculous

30. Microwaves And Health

31. Radio Waves Longest waves. Lowest Energy. Lowest temperature.
Radio size ranges from a few centimeters up to mountain size.
The radio we listen to picks up the coded radio waves and decodes them into sound.
Devices that use radio waves:
Phones, Garage door openers. Wireless network in your home. TV broadcasts. Cellphones. GPS. Police radio. The radio.

32. Simple radio waves Radio waves
If you would like to look into this in more detail follow the link:
By tapping the terminals of a 9-volt battery with a coin, you can create radio waves that an AM radio can receive!

33. Radio waves

34. The Sun