Right Angle Prisms
Right-angle prism from Changchun RZ Optical Co.,Ltd. is usually used to turn the optical path or to deflect the image made by the optical system by 90°. Depending on the orientation of the prism, the image can be left-right consistent and upside down or left-right inconsistent with upside down. Right-angle prisms can also be used for applications such as image combining and beam deflection. The efficient internal total reflection of incident light using the critical angle property is one of the basic functions of a right-angle prism.
Right angle prisms are usually coated with some optical film when used. Because of their large contact area and typical angles of 45° and 90°, right-angle prisms are easier to mount and have better stability and strength against mechanical stress than ordinary mirrors. They are the best choice for all kinds of optical parts for devices and instruments.
Classification and characteristics
UV Fused Silica Right Angle Prisms
Uncoated (185 nm - 2.1 µm), UV fused silica right-angle prisms can be selected if higher UV band transmission or lower thermal expansion coefficients are required. UV-grade fused silica has high transmission in the deep UV with little to no laser-induced fluorescence (measured at 193 nm), making it ideal for UV to NIR applications. For a given wavelength, the refractive index of UV fused silica is smaller than that of N-BK7.
N-BK7 right-angle prisms
Uncoated (350 nm - 2 µm), if the additional benefits of fused silica are not required, choose the N-BK7 right angle prism. n-BK7 has excellent transmittance in the visible and NIR portions of the spectrum. In addition, N-BK7 is a viable option for UV applications at wavelengths down to 350 nm. For applications requiring the highest transmittance, please see below for N-BK7 prisms coated with enhanced transmittance film.
The PS911K blade prism has similar performance to the standard N-BK7 right angle prism, but the ps911K has a precise 90° angle between the two right angle surfaces without a blunt edge. This means that the through-aperture extends across the entire surface, so it is ideal for applications that require a larger through-aperture. It also offers better surface flatness and optical quality.
Calcium Fluoride Right-Angle Prisms
Uncoated (180 nm - 8 µm), calcium fluoride right-angle prisms are the choice for applications requiring high transmittance in the 180 nm to 8 µm wavelength range. Calcium fluoride materials have a low refractive index, ranging from 1.35 to 1.51 in the 180 nm to 8 µm wavelength range, and also have a very high laser damage threshold. Calcium fluoride is also quite chemically inert and possesses superior hardness compared to fluorides such as barium fluoride, magnesium fluoride, and lithium fluoride.
Zinc selenide right-angle prisms
Uncoated (600 nm - 16 µm), zinc selenide is an ideal optical material for use in the 600 nm to 16 µm range and is characterized by low absorption (including the red band of visible light) and good thermal shock resistance. Zinc selenide is ideally suited for use in CO2 lasers operating at 10.6 µm, including CO2 lasers using He-Ne laser alignment.
Gloves should be worn when holding the optical components. This is especially important when you are using zinc selenide because the zinc selenide material is toxic. For your safety, follow all specific precautions, including wearing gloves when holding the prism and washing your hands thoroughly after use. Because of the low hardness of zinc selenide, careful handling is required to avoid damaging these prisms.
