The main components of optical devices are spherical lenses - elements bounded by either two spherical surfaces, or spherical and flat surfaces. Spherical lenses are used to transform the shape of radiation beams and build images of objects.
Protective windows shaped as spherical domes are used to solve some specific problems. Usually, the domes are used in devices operating under high pressure, with high velocities of incoming air or liquid flows. According to their configuration, the hoods can be smaller than hemispheric, hemispheric and hyperhemispheric.
Plane-parallel windows are used in optical devices as protective windows, light filter substrates, and compensators for spherical aberration. The use of wedge-shaped windows can be similar, and their specificity lies in the ability to deflect the beam and/or exclude the appearance of flare from the second surface.
Sapphire, due to its unique physical properties, can be used for the manufacture of optical products operating under extreme conditions, i.e. when exposed to high temperatures, pressures, mechanical loads, corrosive environments and radiation. For the successful application of such optical products, the quality of the polished surface is critical.