- #1
Crystal037
- 167
- 7
- Homework Statement
- Why parallel beam of light is used for ydse?
- Relevant Equations
- I(resultant) = I1+I2+rt(I1*I2cosx)
Where x is the phase difference
I know that ydse is based on interference of light when it passes through an obstacle having almost same aperture as the wavelength of light. Also they should be coherent to have a constant phase difference at every point. But I don't get why the light beams should be parallel?