Thanks to Sample Space, OptiCool Can Be Expanded to Feature a High Magnetic Field Sample Station
When it comes to experiments requiring low temperatures, high magnetic fields and low vibrations, the range of cryostats that can be used is not exactly huge. If, moreover, a large sample area is required, the only available choice is OptiCool.
OptiCool is a powerful optical cryostat that can be directly mounted on an optical table. Instead of the usual superconducting solenoid, it features a 7 Tesla split-coil magnet. This allows optical access both through a top window and several side windows and provides for a generous, free sample space with a diameter of 89 mm.
Common cryogenic sample stations offer a field strength of just up to 3 Tesla and limited optical access. The OptiCool sample space is large enough to accommodate four XYZ positioning systems and a stationary sample holder. Thus, it can easily be expanded to provide an automated sample station with 7 Tesla field strength. The low vibration level of only 10 nm (peak-to-peak) ensures that the measurement tips do not lose contact with the sample. The contact pressure of a commercially available cryogenic positioner is significantly lower than that of a manual arm as used in cryogenic sample stations.
Usually, the measuring tips of a sample station are cooled, but are still warmer than the sample. This causes the sample to be heated by the tips during measurement. In the OptiCool, the positioners and thus the measuring tips have the same temperature as the sample holder.
Usually, the camera of a sample station can only show the position of the measuring tips. In the OptiCool, the working distance to the sample is significantly shorter than in solenoid magnets, so that a lens with a short working distance and high NA can be installed. Thus, combined optical and electrical measurements may be performed in addition to optical excitation. A corresponding setup was recently installed at Fraunhofer IPMS in Dresden.
