This tester is a bilateral image shearing interferometer used for quickly and easily setting the collimation of laser beams. It is superior to other types of designs in that the fringes are easily compared against themselves on the bright, split image viewscreen. Other designs require user to align the rotation of the entire field of view of fringes to a predetermined reference line. It is useful in the optics lab or on any test bench for setting up collimators. To set up a collimator for minimum divergence, just direct the beam into the open aperture of the ParaLine™ and adjust the collimator until the fringes are equivalent on both sides of the viewing screen. Available in wavelength ranges from the visible to the infrared. These individual design wavelengths and wavelength ranges offer increased collimation accuracy over a broad spectral range. No batteries or electronics.
Principle of Operation: The beam enters the open aperture of the cube housing and is incident on an angled precision glass wedge. The light is split into two parts, interferes in the wedge and is observed in the viewscreen. Comparison of the interference fringes on each side of the viewscreen determines the amount of divergence or convergence, although it is primarily a qualitative inspection. Whenever the ParaLine™ is oriented so that the open aperture is on the “top”, divergence and convergence can be determined. If the tested beam is convergent, the left side of the viewscreen will have larger fringes than the right. If the tested beam is divergent, the left side of the viewscreen will have smaller fringes than the right. If the beam is collimated, the fringes will be equal.
532nm: 4 - 10
633nm: 3 - 7
600 - 800nm: 3 - 7
800 - 1000nm: 3 - 7
1000 - 1500nm: 3 - 12
Note:#54-171 and #56-481 have a red enhanced filter for viewing screen. #56-480, #56-482, and #56-483 have a frosted window for viewing screen. Tester is not for high-powered applications. IR viewer/camera required to visualize fringe pattern for IR collimation testers.