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Following the discovery of so called non-diffracting Bessel beams [1], they have been used for a number of exotic purposes such as trapping single atoms and aiding in the discovery of exoplanets. We discuss more mundane but practical methods applicable to precision engineering, and the physical ray tracing of a ball lens in transmission to determine if it behaves as geometrical optics predicts.

The article demonstrates a new approach for achieving high-accuracy alignment with a Bessel-Gauss Beam by utilizing its property of propagating as a paraxial ray. © 2024 OSJ

In this paper we step back from complex CGH patterns used to test aspheric and freeform optics to ask what can be done with the simplest CGH patterns and the high precision of pattern location on a photomask substrate4. We first describe the use of patterns of equally spaced concentric circles to create an axis in space perpendicular to the CGH plane, and the Fresnel zone patterns that produce points in space when illuminated with a point source of light.

Optical aspherical surfaces have become more widely used as they offer advantages such as improved image quality,
compact design, increased light gathering, and reduced distortion. However, measuring aspherical surfaces presents
challenges due to their non-spherical shapes. The primary difficulties include the complexity of surface geometries and
the need for specialized metrology equipment. These challenges require advanced measurement techniques to ensure
accurate characterization and quality control of aspherical surfaces in various applications. This paper introduces an
innovative, AI-driven solution for the measurement of aspherical surfaces within the image space, offering a flexible
optical metrology tool for measuring aspherical surfaces. This approach is characterized by its ability to deliver rapid and
cost-effective integration without the need for custom, complex optics.

Optical aspherical surfaces have become more widely used as they offer advantages such as improved image quality, compact design, increased light gathering, and reduced distortion. However, measuring aspherical surfaces presents challenges due to their non-spherical shapes. The primary difficulties include the complexity of surface geometries and the need for specialized metrology equipment. These challenges require advanced measurement techniques to ensure accurate characterization and quality control of aspherical surfaces in various applications. This paper introduces an innovative, AI-driven solution for the measurement of aspherical surfaces within the image space, offering a flexible optical metrology tool for measuring aspherical surfaces. This approach is characterized by its ability to deliver rapid and cost-effective integration without the need for custom, complex optics.

Bessel beams have found use in the alignment of transmissive optics for some time. They are also used for the alignment of reflecting optics when used in the imaging mode, that is, when the wavefront is near spherical. However, there are cases where it would be useful to use the Bessel beam for alignment of far-off axis aspheres to order to get the asphere aligned close enough to its final position that light will go through the system in the imaging mode. In another mode, the Bessel beam is used to determine the normal to a free form surface.