Holographic optical element

Abstract

A holographic optical element is provided for measuring the dimension and position of an object with aid of a deflected laser beam generated by a monochromatic and coherent laser light source that sweeps across an angular range to produce a fan-shaped reference wave front. The element includes at least two interference patterns. Each interference pattern is created through simultaneous exposure of the element to the fan-shaped reference wave front generated by the monochromatic and coherent laser light source and a parallel partial wave front generated by the same monochromatic and coherent laser light source and hitting the element at a different angle than the reference wave front. The number of parallel partial wave fronts used for the exposure of the element corresponds to the number of interference patterns, and if the parallel partial wave fronts are virtually extended through the holographic optical element, they intersect behind the element in a center of a measuring field.

What is claimed is:  
     
         1 . A holographic optical element for measuring at least one of the dimension and position of an object with aid of a deflected laser beam generated by a monochromatic and coherent laser light source that sweeps across an angular range to produce a fan-shaped reference wave front, the element comprising: 
 at least two interference patterns, wherein each interference pattern is created through simultaneous exposure of the element to the fan-shaped reference wave front generated by the monochromatic and coherent laser light source and a parallel partial wave front generated by the same monochromatic and coherent laser light source and hitting the element at a different angle than the reference wave front, wherein the number of parallel partial wave fronts used for the exposure of the element corresponds to the number of interference patterns, and wherein if the parallel partial wave fronts are virtually extended through the holographic optical element, they intersect behind the element in a center of a measuring field.    
     
     
         2 . The element of  claim 1 , wherein the at least two interference patterns comprises at least three different interference patterns.  
     
     
         3 . The element of  claim 2 , wherein the at least two parallel partial wave fronts are all located in a single plane.  
     
     
         4 . The element of  claim 3 , wherein an angle between the reference wave front and a common plane for the parallel partial wave fronts is 40 to 50° and a bisector of the angle is positioned perpendicular on a plane for the holographic optical element.  
     
     
         5 . The element of  claim 1 , wherein the element includes a plurality of sections, and each section has a respective one of the interference patterns and the sections are spatially separated from another section.  
     
     
         6 . The element of  claim 1 , wherein the at least two interference patterns at least partially overlap one another.  
     
     
         7 . A measuring arrangement, comprising a transmitting part for generating a laser beam and a receiving part, wherein both parts include a holographic optical element and the holographic optical element of at least the transmitting part comprises the holographic optical element according to  claim 1 , said arrangement being adapted to be used to measure at least one of the dimension and position of an object with the aid of the laser beam, which is deflected so that it sweeps across a specific angular range.  
     
     
         8 . The arrangement of  claim 1 , wherein the holographic optical element is a holographic film plate.  
     
     
         9 . A method of measuring at least one of a dimension and position of an object with a laser beam that sweeps across a specific angular range, comprising utilizing the holographic element of  claim 1 .  
     
     
         10 . The method according to  claim 9 , wherein the object comprises one of a cable, profile, and a pipe.  
     
     
         11 . A device for measuring at least one of the dimension and position of an object, the device comprising: 
 a transmitter part for generating a monochromatic light beam and a receiver part, wherein the transmitter part and the receiver part each include a holographic optical element, wherein the transmitter part includes means for deflecting the light beam in the transmitter part through an angular region onto the holographic optical element in the transmitter part, and wherein at least one of said holographic elements comprises the holographic element according to  claim 1.