I have a simple setup with a diode laser and an object placed in front of it. I want to observe the edge's shadow clearly.
However, I get this very annoying effect of diffraction and interference around the edges of the object(see pic below)
Is there a way to reduce this effect? Spatial coherence is mandatory for my setup, but spectral/temporal isn't.
The two solutions I've thought of are:
(a) using a temporally incoherent source, like an arc lamp (which unfortunately won't be as spatially coherent as a laser) and
(b) somehow randomly scrambling the phase through the beam's section
I'm not good with optics though so I don't know if these will work or how to implement them.
Different approaches with regards to the light source are welcome.