Quantum computers use the laws of quantum mechanics and they are a promising research area. Trapped ions are often used as the core of qubits because of their ability of staying in superposition for a long time. A combination of a Paul trap and a specialized trapped ion lens can be used to slow down trapped ions and modify their states. These lenses are typically color corrected for a few wavelengths and have a very high NA in order to create a fine focus on top of the ion which is located at a vacuum chamber.
Normally customized lenses are necessary but sometimes a catalog lens can be used or modified a little bit for the application. Both kinds can be offered by Sill Optics.