• Qualitative Beam Collimation Test for Beams with Diameters Ø2.5 – Ø5 mm
• <10% Beam Pick-Off
• Magnetic Steel Balls Secure the Plate to the Base
• Imperial and Metric Threaded Mounting Holes

This Shearing Interferometer can be used with incident beams with Ø2.5 – Ø5 mm. The interference pattern is sensitive to the beam divergence and can be used to qualitatively determine whether the beam is collimated. The design consists of a wedged optical flat mounted at 45° and a diffuser plate with a ruled reference line down the middle. The diffuser plate is used to view the interference fringes created by Fresnel reflections from the front and back surfaces of the optical flat. If the beam is collimated, the resulting fringe pattern will be parallel to the ruled reference line. In addition to the degree of collimation, the fringes will also be sensitive to spherical aberration, coma, and astigmatism.

The plate of the SI050 has three steel balls fixated to the bottom of the plate, which attach magnetically to the base. This magnetic retention mechanism enables easy swapping of plates when different beam diameters are used. In addition, there is a hole drilled into the back of the base plate, thus enabling the light that is transmitted through the wedged optical flat to continue unimpeded. The base plate, diffuser plate, and shear-plate come packaged in an aluminum carrying case.

• Wedge Angle: 83 arcsec
• Diameter: 7.94 mm +0/-0.25 mm
• Thickness: 1.30 mm ± 0.25 mm
• Approximate ?OPL: 3.31 mm
• Dimensions: 50.8 × 48.3 × 55.9 mm