Phase masks

Phase masks affect only the phase and not the amplitude of the transmitted light. Thus they offer low-loss operation compared to amplitude masks. Customized UV-transparent phase masks from SiO₂ are fabricated by laser ablation according to a patented process. Especially masks with medium feature sizes ranging from 10 µm to a few 100 µm are ideally producible with this method. They can be used e.g. as diffractive beam splitters or projection masks for demagnifying imaging. The phase masks are optimized for the specific application wavelength, which can be in the range from the deep UV to the near infrared.