| A | B |
|---|
| Geometric Optics | Used for objects much larger than wavelength |
| Wave Optics | Used for objects whose size in on order of wavelength |
| Constructive Interference | Waves adding in phase |
| Destructive Interference | Waves adding out of phase |
| Coherance | Change phases together |
| Wavefront splitting | Create two coherant waves by using two slits |
| Amplitude splitting | Create coherant waves by using a half silvered mirror |
| Hard reflection | 180 degree phase change |
| Soft reflection | No phase change |
| Transmission Grating | Opaque plate with transparanent slits |
| Reflection Grating | Regularly spaced reflective surface |
