Beam profile has grainy/multimode pattern, EO says it's due to different emissivity of each phosphor atom. How do I work with this?

I'm required to make a jig that measures the divergence angle of a collimated beam. The setup is straightforward as shown below. The single-mode fiber optic cable, collimator & NIR camera are...

15 June 2022 1,812 0 View