Published Papers

The subject of this Chapter is prompted by several questions over the last couple of months concerning the alignment of tube lenses to high power microscope objectives. In most microscopes these days the objectives are designed as finite to infinite conjugate optics so there is a need for a “tube” lens to focus the object […]

We use a known optic, a catalog off-axis parabola, as a reference to both model in Zemax and to align while tracking the position of the focus in 3 degrees of freedom (DOF) and the tilt of the auto-reflecting flat in 2 DOF to demonstrate a systematic approach to alignment. The aberrations present at each step of the experimental procedure are monitored using an autostigmatic microscope.

In this study, we explore the behavior of Bessel beams as they propagate through a misaligned apertured optical system in practice. Based on experimental observations, we propose what we believe to be a novel hypothesis that a Bessel beam propagating through an optical system behaves identically to a paraxial ray under certain conditions. We then derive analytical formulas for the propagation of Bessel beams in Cartesian coordinates and the Huygens-Fresnel principle. Additionally, another simulation employing Gaussian decomposition was conducted, and we compared both simulations with experimental results, demonstrating a high correlation. Our findings indicate that Bessel beams can be interpreted as meridional rays when passing through misaligned spherical surface systems, allowing us to achieve quasi-ray tracing in practice. We further discuss the significance of utilizing this property of Bessel beams for precise optical alignment, highlighting its potential to enhance the accuracy and efficiency of optical systems.

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.