- Since the pump is now at 2° incidence, the reflection from the sample was hitting the mount of the periscope. Without moving the periscope, I collected the reflection with a mirror and I redirected it outside with another mirror through a hole in the enclosure. Then I put a blackhole damper to absorb the power. I decided to bring the power outside to avoid heat generation inside the enclosure that may cause temperature fluctuations and noise at low frequency on the absorption signal.

- I also added a shutter after the chopper, to be able to close the pump for few seconds (not more otherwise the shutter melts) and be able to move the sample away from the pump path without burning the sample mount.

- The pump path at the ground level of the optical table was covered with a black paper enclosure. I replaced it with black anodized aluminum panels to reduce the generation of dust.