Double-Slit Interference of Light
How it works
- Light from the double slits converge on the middle bright patch, having travelled the same distance.
This means that constructive interference takes place and a maxima of light appears on the screen. - On the second bright patch, the light from the bottom slit has to travel further to get to the second bright patch.
Because light appears, the light waves from both slits must be in phase, meaning the light from the bottom slit has travelled one extra wavelength than the light from the top slit. This light is dimmer. - On the third bright patch, the light from the bottom slit has to travel even futher than the light from the top slit. Because light appears (allbeit very dim), the light from both slits must be in phase, meaning the light must have travelled two extra wavelengths.
Working with lasers
Working with lasers
- Never shine a laser at a person
- Wear safety glasses
- Avoid shining the laser at a reflective surface
- Have a warning sign on display
- Turn off the laser when it is not being used