A method and device for synthesizing non-diffraction beams in the shadow area of ​​conical lens

Abstract

The invention provides a method for synthesizing non-diffraction beams in the shadow area of a conical lens. The method comprises the following steps: (1) parallel laser beams illuminate the conical lens, wherein the parallel laser beams are parallel to the axis of the conical lens; (2) a focusing lens group is put on the section of the shadow area of the conical lens, and the focal length of the focusing lens group is adjusted, so that the conical lens is on the focal plane of the focusing lens group; (3) the non-diffraction beams are obtained behind the focusing lens group. The method can obtain approximate non-diffraction beams in a super-long range, the limitation that the cone angles of the spreading distance of the non-diffraction beams for the conical surface and the bottom surface of the conical lens are small and are difficultly processed is eliminated. The invention further provides a device for synthesizing the non-diffraction beams in the shadow area of the conical lens, and the device has the advantages of being simple in structure, convenient to mount and convenient to realize.

Description

technical field [0001] The invention belongs to the field of optical diffraction applications, and in particular relates to a method and a device for synthesizing non-diffracting beams by utilizing the shadow area of ​​a conical lens. Background technique [0002] Due to the constant characteristic of the cross-sectional light intensity distribution of the non-diffraction beam along the propagation direction, it is widely used in many fields, for example, it is often used as an ideal space straight line reference in precision engineering. There are many ways to synthesize near-diffraction-free, and the more common methods include annular slit method, Fabry-Perot interference method, and the most concise conical lens synthesis method. However, the diffraction-free range of these traditional synthesis methods is limited by parameters such as optical devices or structures, and it is difficult to achieve non-diffraction in the ultra-long-distance range; and the two methods of an...

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Problems solved by technology

However, the diffraction-free range of these traditional synthesis methods is limited by parameters such as optical devices or structures, and it is difficult to achieve non-diffraction in the ultra-long-distance range; and the two methods of annular slit method and Fabry-Perot interference method optically realize It is more complicated, and the processing of high-quality small cone angle and large aperture conical lens is difficult, which hinders the application of non-diffracting beams in super-large-scale spaces

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