Hi everyone! I work with a dual view lightsheet microscope, with the laser launched from an NKT select with two outputs. We then input the fiber in an ASI scanner. One side has consistently performed worse in terms of sheet thickness with the same optical path, bugging me for a while. The other day I noticed that the fiber output on that side looks clearly worse, see attached pictures. Is the ‘cleaner’ side even good enough? Can I clean the fiber output face? How would I do that safely? Thanks!
Welcome Milo!
Thorlabs has a pretty good guide for fiber polishing:
You can also get supplies from them as well:
Before committing to re-polishing your fiber, I would suggest inspecting it first. Thorlabs also has a tool for that: Thorlabs .
Then, if you see that there are debris on the core, I would start by trying to clean it. First blow some air to see if it goes away (use clean air, from a can or if you have compressed air from your lab make sure it is filtered!). If it doesn’t you can use something like isopropyl alcohol with a lens tissue (I like to put the tissue on top of the fiber tip, put a drop of IPA, and pull on the tissue parallel to the face of the fiber). If it still doesn’t go away, and it looks more like scratches, you could then resort to polishing but I have to warn you its a rather delicate procedure, and you may want to practice on a “dummy” fiber first (depending on how precious that fiber is…). One of the important thing to figure out is whether it is an angled face or not (that’s the different between FC/PC and FC/APC for example, where PC is “Polished Connector” and APC is “Angled-Polished Connector”). Because you need different tools then. Also, depending on how the fiber was polished before (and if its been re-polished before), it is not guaranteed to have enough room for another touch-up.
EDIT: the material of the ferrule is also an important parameter to consider, in your picture it looks metallic (as opposed to ceramic) and Thorlabs has different polishing sheets for each type. Double check what yours need.
Long story short, I would only do polishing after exhausting the other options, and even then, unless you are used to doing it, I would practice it a bit before, and check the quality of your work with the fiber inspection tool.
Take care,
Omni
If you haven’t tried it already, you could swap the fibers between the two ports to verify that the worse performance is only due to a fiber to fiber difference.