What are the advantages of fused silica beamsplitters?
Core advantages of fused silica beamsplitters
(1) Ultra-wide spectral transmission
Deep Ultraviolet (DUV) to Near Infrared (NIR) are applicable, especially suitable for:
UV spectroscopy (e.g. 193 nm excimer laser systems).
UV laser processing (e.g. 355 nm UV laser cutting).
Infrared optics (e.g. 1550 nm fiber optic communication).

(2) High thermal stability
Extremely low coefficient of thermal expansion (near zero expansion), suitable for:
High and low temperature environments (e.g. space optics, laser refrigeration systems).
High power lasers (minimal thermal distortion).

(3) High laser damage threshold (LDT)
Laser damage resistance is better than BK7 and SF11, suitable for:
High-energy laser systems (e.g. Nd:YAG, femtosecond lasers).
UV laser (e.g. KrF 248 nm, ArF 193 nm).

(4) Low fluorescence & high chemical stability
No impurity fluorescence background, suitable for fluorescence microscopy, Raman spectroscopy.
Resistant to acid and alkali, humidity, suitable for biochemical testing, harsh environment.

What materials are commonly used for beamsplitters?
Material	Transmittance (nm)	Refractive Index (@587.6nm)	Characteristic	Typical Application
BK7 Glass	350-2000	1.5168	Low cost, high homogeneity, easy processing	Visible NPBS, general spectral system
Fused Silica	180-2500	1.4585	High UV transmittance, low thermal expansion	UV/VIS PBS, laser system
CaF2	180-8000	1.4338	Wide band, humidity intolerant	UV/IR spectroscopic prisms
Calcite	350-2300	no=1.658, ne=1.486	Strong birefringence, natural crystal	Polarizing beam-splitting prisms (Glan prisms)
Silicon	1200-7000	3.422 (@1500 nm)	High refractive index, impervious to visible light	Infrared PBS, thermal imaging systems
ZnSe	600-16000	2.403 (@10.6 μm)	Excellent infrared transmission, expensive	CO₂ laser spectroscopy, infrared spectrometer