The advantages are as following:

• Enlargement of ~2.4X of the image in a diamond anvil cell
• Improvement of resolution, as a spherical anvil works as a solid immersion lens
• The image is free of not only spherical aberration, but also from coma and astigmatism in a zone around the surface centre, making the alignment procedure easier
• Pressure measurement improved precision on a Raman signal from the centre of the culet of the diamond anvil
• In situ single crystal XRD experiments with laser heating can be realised with stationary laser-heating setups
• The angle of incidence of the incoming laser beam remains normal to this surface and focused on the sample, while the DAC is rotated during the XRD data collection
• The object observed through the anvil does coincidence with the object’s physical position along the optical axis, making the optical and X-ray aligment more simple and accurate. No refraction correction is needed once the sample is aligned to the optical focal point.