Prisms

Dispersion Prisms

Dispersion Prisms

Besides the Reflection Prisms, Foctek also offers the Dispersion Prisms. The most typical dispersion prism is equilateral prism made of high difference of refaction indexes for different wavelengths. The dispersion prisms of special use are: Litrow prisms, Pellin-Broca prisms, Brewster prisms, Amici Prisms.
EQUILATERAL dispersion prism
 
EQUILATERAL dispersion prisms have three equal 60° angles, which are made of optical materials with high difference of refraction indexes for different wavelength, such as the SF10.
ISOSCELE prism
 
ISOSCELE dispersion prisms have the three angle with 30°- 60°- 90°. The prisms are also made of optical materials with high difference of refraction indexes for different wavelength, such as the SF10.
LITTROW prism
 
Light crossing the LITTROW prism is spectrally dispersed with simultaneous inversion of the path of rays caused by the reflection taking place on the back surface of the prism. The reflection surface has to be mirrored coating.
PELLIN - BROCA prism
 
PELLIN - BROCA prism is a special kind of dispersion prism. Besides dispersing properties, the prism has the property of diverging rays by 90°. By rotating the prism around it's A axis, you can select the wavelength what you require.
BREWSTER prism
 
BREWSTER prism is recommended for polarized light. P-polarized beam is transmitted with no losses when input beam is at the Brewster angle, while the S-polarized beam is reflected.
AMICI prism (Direct Vision Prisms)
 
The AMICI prisms generate dispersion of polychromatic light with simulaneous correction of divergence. All the dispersed beam output from the prism are parallel to the input beam. These Prisms consist of three prisms, which are cemented together. Two of the three prisms (A prism in the left draft) are made of different material to the other prism (B prism in the left draft). Typical combination of materials are Flint galss for A and Crown glass for B.

Material

On request, for example, N-BK7, Fused Silica, MgF2, N-SF10

Range of Size

4 ~ 300mm

Dimension Tolerance

+/-0.1 mm

Clear Aperture

>90%

Angle Accuracy

+/- 3 arc min

Pyramid error

+/- 5 arc min

Flatness @633 nm

<Lambda/2

Surface Quality

60/40

Coating

Uncoated,AR,HR,PR coated ect.

Note:
According to Customer's requirement, we can make non-standard Dispersion Prisms with significantly higher optical parameters. Surface quality better than 10/5, flatness better than 10, angle tolerance better than +/-10 arc sec is available. Prism in mounting is also available.

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