L1 Light Sources and Light Rays

These demonstrations offer a simple introduction to the production and transmission of light, and to basic principles of ray optics.

Articles
Image	Title
	L1-01: ARC LAMP - PROJECTION OF ARC Direct projection of side view of the arc of a carbon arc lamp.
	L1-02: TUNGSTEN-HALOGEN LAMP - PROJECTION OF LAMP View an operating tungsten-halogen lamp.
	L1-03: LIGHT BULB WITHOUT VACUUM Show what happens to a lighted filament in the presence of air.
	L1-04: POINT SOURCE - FLASHLIGHT BULB Demonstrate optical characteristics of a "point source"
	L1-05: PERSISTENCE OF A FILAMENT Demonstrate that high-frequency AC looks like DC.
	L1-11: INVERSE SQUARE LAW - LIGHT BULB AND RADIOMETER Demonstrate that light obeys the inverse square law.
	L1-12: INVERSE SQUARE LAW - OVERHEAD PROJECTOR AND TWO-METER STICK Show that light obeys the inverse square law.
	L1-21: PINHOLE IMAGE - GROUND GLASS SCREEN View individually a pinhole "image."
	L1-22: OPTICAL BOARD - PINHOLE CAMERA Demonstrate how a pinhole "image" is formed.
	L1-23: PINHOLE VIDEO CAMERA Produce video images with a pinhole camera.
	L1-31: LASER LIGHT CAVITY Demonstrate how a laser cavity works.
	L1-32: VISIBLE LASER Show what the inside of a laser looks like, and to show that the laser removes lots of spectral components from the light in the tube and only lets one wavelength out.
	L1-33: LASER BEAM EXPANDERS Expand a laser beam to uniform 10mm or 40mm diameter.