Penta Prisms (PTP)
Reflects rays through a 270° angle by two reflections
- (does not invert the image)
- Movement of the prism
- (does not affect the right angle at which rays are reflected)
- Dimensions : A = B = H
- Penta prisms are offered as uncoated
- Coatings are available upon request
Penta prisms are extremely useful in alignment systems as they define a right angle very precisely and independently of angle of incidence. Rays entering one face emerge from the adjacent face at precisely 90° after they have undergone two reflections inside the prism for a total of 270°. The penta prism acts as a turning mirror which is insensitive to alignment. For custom applications, anti-reflection coatings are applied to the entrance & exit surfaces. Either metallic or dielectric high reflector coatings are applied to the 2 reflective surfaces.
Material: |
BK7A |
Surface Flatness: |
< λ / 4 @ 633 nm |
Surface Quality: |
<40 / 20 |
Dimension Tolerance: |
<+ 0.00 / – 0.20 mm |
Angular Deviation |
<30 arc sec |
Clear Aperture: |
> 85% in central circular dimension |
Bevel: |
0.3 mm (typical) x 45° |
Penta Prisms (PTP)