MarcEisenmann - 00:14, Thursday 15 June 2017 (504)
End room optics
Participants : Eleonora, Marc
Yesterday, we finished the installation of the optical components to extract the signal from the end mirror on a photodiode and a CCD camera.
The optical bench is composed of one lens (focal length = 1m) inside the end chamber, one periscope, another lens (focal length = 0,150 m), one dichroic mirror, one beam splitter, one CCD camera and a photodiode.
Instead of using a periscope fixed on an elevated optical frame, we built a higher periscope.
On this periscope, 2 Aluminium mirrors (TFA-50-C08-10) were mounted. We also checked that they were reflective for infrared : 92,08% at 45°
The 2 lenses are used to get a smaller beam size onto the photodiode and the CCD camera. Currently, the beam hitting these two components is 6,67 times smaller that the beam hitting the end mirror. We might have to change the second lens as we expect a drastic change in the beam shape when we will remove the tube windows.
The beamsplitter will also be changed as it is supposed to be working for green (instead of infrared for the moment). It is still able to split the beam in two, so we were able to detect the beam in the photodiode and send it back to the central room.
Yesterday, we finished the installation of the optical components to extract the signal from the end mirror on a photodiode and a CCD camera.
The optical bench is composed of one lens (focal length = 1m) inside the end chamber, one periscope, another lens (focal length = 0,150 m), one dichroic mirror, one beam splitter, one CCD camera and a photodiode.
Instead of using a periscope fixed on an elevated optical frame, we built a higher periscope.
On this periscope, 2 Aluminium mirrors (TFA-50-C08-10) were mounted. We also checked that they were reflective for infrared : 92,08% at 45°
The 2 lenses are used to get a smaller beam size onto the photodiode and the CCD camera. Currently, the beam hitting these two components is 6,67 times smaller that the beam hitting the end mirror. We might have to change the second lens as we expect a drastic change in the beam shape when we will remove the tube windows.
The beamsplitter will also be changed as it is supposed to be working for green (instead of infrared for the moment). It is still able to split the beam in two, so we were able to detect the beam in the photodiode and send it back to the central room.
Images attached to this report
