Holographic test plate for positioning and aligning pipes
A target plate (Z) according to the invention for positioning components, in particular pipes (R 1 , R 2 ), has a holographic optical element as a holographic diffusor. By means of the diffusor, radiation striking the target plate (Z) in the form of a reference beam (RS) can be guided very accurately and virtually without loss into a defined solid angle region (dΩ). Furthermore, the diffusor may have stochastically distributed structures and thus illuminate the solid angle region (dΩ) homogeneously. By means of the target plate (Z), the visibility of the incident reference beam (RS) is increased, and the reference beam (RS) can also be detected independently of position.
1. A target plate, comprising
a first optical transparent surface and
a second optical transparent surface having a target mark for visualization of a reference beam emitted by an optical beam source,
wherein the target plate has a holographic optical element for diverging and deflecting the reference beam into a defined solid angle region by diffraction and the holographic optical element is formed in such a way that, for a phase of a laser beam, an at least partial phase destruction takes place for reducing three-dimensional coherence.
2. The target plate as claimed in claim 1 , wherein the holographic optical element is formed so as to be optically transmittive.
3. The target plate as claimed in claim 1 , wherein the holographic optical element has
a holographic plate or
a holographic sheet or
a holographic film.
4. The target plate as claimed in claim 1 , wherein the holographic optical element has at least one computer-generated hologram.
5. The target plate as claimed in claim 1 , wherein the holographic optical element has a mixed-order diffractive structure.
6. The target plate as claimed in claim 1 , wherein the holographic optical element has a castable surface relief.
7. The target plate as claimed in claim 1 , wherein the holographic optical element is formed in such a way that divergence and diffraction of the laser beam takes place in a
square or
rectangular or
elliptical or
circular
solid angle region.
8. The target plate as claimed in claim 1 , wherein the solid angle region comprises at least one
horizontal angle range of ±45° or
vertical angle range of ±45°.
9. The target plate as claimed in claim 1 , wherein the holographic optical element is formed in such a way that light distribution in the solid angle region has a
homogeneous/constant distribution,
cosine distribution,
cosine to the n th power distribution,
dipole distribution,
quadrupole distribution or
Lambert distribution.
10. The target plate as claimed in claim 1 , wherein optical power in zero-order diffraction of the holographic optical element is less than 2%.
11. The target plate as claimed in claim 1 , wherein scattering efficiency for at least one range of an angle of incidence of the reference beam relative to the target plate of +/−15 degrees decreases by not more than 10%.
12. The target plate as claimed in claim 1 , wherein the holographic optical element is arranged on the second optical transparent surface.
13. An optical system comprising
an optical beam source for emission of the reference beam and
a target plate as claimed in claim 1 .
14. The target plate as claimed in claim 1 , wherein the target plate produces a conical region as the irradiated solid angle region without producing radiant power outside of the solid angle region.
15. The target plate as claimed in claim 1 , wherein an axis of a diffracted beam produced by the diffraction is different than the axis of the reference beam.