SpertrumThe fluoride materials have a wide range of potential optical applications because of their high transparency arising from low-energy phonons and high ionicity. Especially, the calcium fluoride (CaF2) crystal with an optically isotropic fluorite structure has attracted much more attention due to its high transparency in a broad wavelength range, high chemical resistance, high laser damage threshold and low refractive index. The doping of europium elements into CaF2 crystal can change its physical properties, which can be used to realize the various optical integrated devices,such as UV sensor, filter, stepper lens and so on.
Eu:CaF2—A scintillation material with high optical transparency and low phonon energy
Rare earth elements are easily to form clusters in CaF2 crystals, which is beneficial for reducing the doping concentration and maintaining the energy transfer between erbium ions as well. As s one of the phosphors that has efficient excitation in the near UV range, Europium-activated calcium fluoride (Eu:CaF2) is an inert and transparent material with several characteristics that make it attractive for use as a scintillator in radiation detection systems. It has an average light yield of 24,000 photons*MeV–1 and the refractive index is similar to that of many photomultiplier tube windows and optical coupling compounds. Therefore, a high light collection efficiency can often be obtained. Additionally, the maximum wavelength of fluorescent emissions from Eu:CaF2of 435 nm matches well with photocathode photomultiplier tubes. What’s more, Eu:CaF2 can be used in relatively harsh environmental conditions because of its non-hygroscopic nurture and fracture resistance.

Material features

Scintillator properties

Spertrum

Feature
High transparency
High chemical resistance
High laser damage threshold
Low refractive index
Non-hygroscopic nurture
Excellent fracture resistance
Low effective atomic number
Low density
Low phonon energy

Application
Biomedical imaging
Therapeutics
Photonics
UV sensor
Filter
Stepper lens
Pressure marker
Detection of low energy photons and charged particles
2.8 µm lasers
Medical treatments