Rocky Mountain Instrument Co.
1.303.664.5000
 

Optical Components:

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Prisms » Penta Prisms

Penta Prisms deviate a beam by 90º without inverting or reversing the image. These prisms also have the property of constant deviation, which means that the 90º deviation angle applies to all rays transmitted by the effective aperture, regardless of their angle with respect to the optical axis.

Penta prisms are thus very useful in applications where prism orientation cannot be precisely controlled. Due to the geometry of penta prisms, the reflecting surfaces due not utilize total internal reflection and must be coated with a metal or dielectric coating.

 
sketch-penta-prisms
 
RMI Standard Specifications
Materials:
BK7, UVFS, FS,
CaF2
Surface Figure:
BK7, UVFS, FS:
CaF2:
All polished surfaces:
λ/20 at 633 nm
λ/4 at 633 nm
Surface Quality:
BK7, UVFS, FS:
CaF2:
All polished surfaces:
10-5
20-10
Dimensions: A=B=C
Dimensional Tolerance: + 0.000", – 0.010"
Angular Deviation:
≤ 3 arc minutes
Bevels: 0.010" – 0.030" at 45º
Clear Aperture: Exceeds central 85% of diameter