Logo



DPG

19.03.- 21.03.2024
Visit us in Berlin at the DPG Meeting of the Condensed Matter Section


Photonik Tage BB
9.10-10.10.2024
Visit us at the Photonic Days Berlin-Brandenburg

Kösters Interference Double Prisms

Kösters Interference Double Prisms

The prisms are made of fused silica (Homosil) and consist of two identical cemented prisms The angles of these prisms are 30° - 60° - 90°. The long cathetus of one of the prisms is coated with a partially reflecting protected silver layer for the visible spectral range.

A Kösters prisms generates two parallel output beams. It allows a simple realization of a white light interferometer having exactly equal optical length in both arms.

Optical specifications

material fused silica
spectral range 400-700 nm
splitting ratio (unpolarized) 45:45 (±5) %
Polarisationsempfindlichkeit |Rs-Rp|<5%
absorption loss ca. 10%
flatness the surfaces <λ/10
angular tolerance ±1'
angular equality of the prisms ±1''
connection of the prisms cemented

Standard dimensions

side length
20 mm 30 mm 40 mm 60 mm 100mm
height [mm] 10 15 20 30 50
useable diameter [mm²] 9,0 x 9,0 14,0 x 14,0 19,0 x 19,0 28,0 x 28,0 48,0 x 18,0
long cathetus [mm] 17 26 34 52 86
Art. No.
IKP 020 IKP 030 IKP 040 IKP 060 IKP 100

Prices

order no. 1 piece in € 2 piece in € 3-5 piece in €
IKP 020 1548.- 1276.- 1058.-
IKP 030 2003.- 1608.- 1293.-
IKP 040 2633.- 2163.- 1787.-
IKP 060 3977.- 3586.- 3274.-
IKP 100 7382.- 6617.- 6004.-

Price custom version

antireflection coating on entrance and exit surfaces on request
dielectric coatings (absorptionfree) on request
combination of prisms for other interferometers on request