In fact, we have a confocal Raman system in the lab already, but the alignment is completely lost...
In order to dealing with our new baby--graphene, I told to my boss that I want to refurbish the previous Raman system in the lab. Since it is has long fallen into disuse. And once again, I gave myself a challenge, just like the previous work in redesigning the CVD system.
But I have to say this is definitely a wearing job to save this old Raman system.
The confocal Raman system has several parts, laser, confocal microscope, spectrometer, CCD, the most difficult task is how to adjust the laser spot and make it align to the identical light path of signal from sample. I spent almost two weeks adjusting a small piece of filter, namely "notch filter" which is an essential part of confocal Raman system. This small filter is responsible for filtering out the original laser signal from the reflected Raman signal of sample. Even the most subtle adjustment of this filter could lead to significant change in the position of light spot. That's why no one in the lab want to solve this thorny problem!
Anyway, through this experience of refurbishing our old Raman system, I have learned the alignment of optical path, and the basic sense of the optical component as well. After about 1 month wearing job of alignment, the Raman started to work normally with graphene.
