Moving mirror assembly

An FTIR spectrometer contains a single beam optical assembly with, as an essential component, an interferometer - often of the Michelson type - located between the source and the sample (Figure 10.7c). It consists of three active components a moving mirror, a fixed mirror and a beam-splitter. 

With the microchip objective removed, the dichroic beamsplitter should be adjusted so that the excitation beam exits the assembly perpendicular to the table. This will put the dichroic at the desired 45°. The position of the beam on the dichroic beamsplitter should then be checked using a mirror above the objective adapter to direct the excitation beam back out of the cube assembly. This is easily observed with the iris still in place. If the beam is not centered, the dichroic mount can be moved back and forth along the beam path. This may require the use of a washer between the cube and the mount to back it out sufficiently. 

New parts can be constructed during assembly sessions by merging, cutting, or mirroring existing parts. Parts are grouped, moved, copied as instances, and mirrored. Construction can be controlled by an assembly family instance. Assembly families are created by using family tables. Simple tools, such as a reference viewer to see how components are referenced are also very important. 

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