Application Example: Poisson’s Spot

Figure 1. Poisson’s spot irradiance pattern. A 588 nm coherent plane wave source shines behind a circular obstruction with 0.1 mm radius. Coherent irradiance is evaluated at two different distances: On the left side, light 2 mm beyond the obstruction does not undergo significant diffraction. On the right side, light 40 mm beyond the obstruction undergoes Fresnel diffraction and exhibits a characteristic Poisson Spot on axis.

FRED allows for simulation of physical optics phenomena such as diffraction and interference. With this capability, components such as Gaussian laser beams and interferometers can be accurately modeled and incorporated into optical systems.

As an example, the Poisson’s Spot experiment is modeled in FRED. A simple coherent plane wave optical source is created, followed by a small circular obstruction. Coherent irradiance behind the obstruction is evaluated at two different distances to show development of the diffraction pattern.

A full description of this application example can be found here: Poisson’s Spot Application Example

Download the FRED file: poissons-spot.frd