Calcium fluoride (CaF₂) is commonly used for optics looking at the IR and UV spectrums and has a very low change in refractive index with wavelength. It shares similar optical properties with barium fluoride, although it has a transmission that is 2.5µm less into the infra-red. Calcium fluoride is however cheaper than barium fluoride as the optical grade occurs naturally as opposed to BaF2 being man made.
Calcium fluoride can be used for many applications, including vacuum ultra violet, ultra violet and infrared thermal imaging. Calcium fluoride is traditionally used in apochromatic design to reduce light dispersion in lenses, both in cameras and telescopes, and has uses in the oil and gas industry as a component in detectors and spectrometers. Calcium fluoride has low absorption and high damage threshold and as it has a low refractive index antireflective coatings are not commonly used making it an ideal choice of material for optics used in Excimer lasers are a form of ultraviolet laser used in micro-machining, eye surgery and micro-machining devices.
Calcium fluoride is superior to UV fused silica in deep UV applications. It has a transmission greater than 75% between 0.15-9µm and transmits efficiently up to about 8µm transmitting over 90%. Calcium fluoride has a hardness of HK158, which is approximately twice as hard as BaF₂. Calcium fluoride is not readily degraded under normal atmospheric conditions until 600°C when it starts to soften. In dry conditions calcium fluoride has a maximum operating temperature of 800°C. Calcium fluoride can be vulnerable to thermal shock at high temperatures. When calcium fluoride powder is compressed in moulds the resulting material is called Irtran-3.
Knight Optical supply a range of quality calcium fluoride optical components including CaF₂ windows, CaF₂ lenses, CaF₂ prisms, and CaF₂ blanks either from stock or bespoke custom made to your specification for a range of applications. Every component is individually tested by our highly skilled technicians in our state of the art metrology lab to ensure all components meet our high quality standards.
Contact our multilingual technical sales team and discover how Knight Optical’s high quality calcium fluoride optical components and service can improve your instrumentation and supply chain experience.