At the expense of two reflections from the microlens (sitting inside the tube 4 in the above picture) the MIU got better, easier alignment and is not prone to the wear and damage of the gold-coated ball lens. There are two mirrors inside adjustable holders 3 and 5 which are used for coarse and fine alignment of the probe spot to the photodetector 6.
Older PCI instruments could be upgraded with the MIU. In the new version of the software the motorized version of the MIU will be supported, the MIUM. When the substrate material or refractive index is changed or when a new length of the sample is entered the MIUM will immediately move to the corresponding position.
