How Is Spatial Coherence Derived from Heisenberg's Uncertainty Principle?

[Gavroy]

hi

does anybody know a derivation of the formula for spatial coherence:

a sin(beta) << lambda /2

where a is the length of radiating object

and beta is half the opening angle.

 

[RedX]

hi

does anybody know a derivation of the formula for spatial coherence:

a sin(beta) << lambda /2

where a is the length of radiating object

and beta is half the opening angle.

I think it follows from Heisenborg's uncertainty princpal.

$$\Delta x \Delta p=\frac{h}{2}$$
$$\Delta x= \frac{\lambda}{2}$$
$$a\sin(\beta)= \frac{\lambda}{2}$$