I’m setting up Nikon Ti2 with a manual TIRF module. I’m using LU-N4 laser launch equipped with four laser lines. The powers at the fiber output are 15-20mW for all four lasers (at 100% setting), but they are only ~0.5mW at the sample plane. Is this level of loss normal for the manual TIRF moddule+filter cube? Or is it possible I configured the system wrong? The light out of an objective seems well-collimated.
If you haven’t already solved this… Can you describe the setup a bit more? The fiber from the LU-N4 is connected directly into the manual TIRF module? The manual TIRF module is a Nikon product or something that you put together?
I would not be surprised by that you’d lose 1/2-2/3 of the power between the fiber and what comes out of the objective, however 20x does seem a bit large. How much power to you measure going into the objective? You could measure this by removing the objective or rotating the turret to a position that doesn’t have an objective.