Microoptic double beam system for reflectance and absorption measurements at high pressure

A microoptical double beam system for reflectance and absorption measurements from small samples (less than 100 μm size) in the spectral range of 0.5–5 eV is described. In conjunction with a diamond anvil high-pressure cell the system is particularly useful for optical reflectivity measurements at pressures up to 400 kbar. Examples are furnished illustrating the use of the system in high-pressure investigations of the stage two graphite intercalation compound C24SbCl5 and of solid oxygen. We briefly comment on Raman spectroscopy at high pressure.