Characterization of the Propagation Route of Light Passing Through Convex Lens

Existing optical theory states that the light directed to the optical center of the convex lens will travel in a straight line. Does the theory hold? If this is true, then why the images formed by the camera lens tends to be distorted? To answer the question, this paper studied the propagation mode of light passing through convex lens. Specifically, assuming the propagation medium on both sides of convex lens is homogeneous, we propose an angular affine transformation (AAT) theory. Based on the proposed theory, we first derive the refractive index of convex lens as well as the method of calculating the normal direction of each point within the radius of convex lens radius and then derive the refraction direction of each point within the radius of convex lens, thus completely characterizing the path diagram of light directed to the optical center. The correctness of the proposed theory has been verified using two sets of experiments: characterization of the route of light passing through the convex lens as well as camera imaging experiment. From the results, it can be concluded that the light directed to the optical center of convex lens does not travel in a straight line, but in a refraction line.

Diffusive dynamics of charged nanoparticles in convex lens-induced confinement

Hydrodynamic effects influence the dynamics of nanoparticles in confined geometries.

Development and Implementation of a Rotating Nanoimprint Lithography Tool for Orthogonal Imprinting on Edges of Curved Surfaces

Uniform molding and demolding of structures on highly curved surfaces through conformal contact is a crucial yet often-overlooked aspect of nanoimprint lithography (NIL). This study describes the development of a NIL tool and its integration into a nanopositioning and nanomeasuring machine to achieve high-precision orthogonal molding and demolding for soft ultraviolet-assisted NIL (soft UV-NIL). The process was implemented primarily on the edges of highly curved plano-convex substrates to demonstrate structure uniformity on the edges. High-resolution nanostructures of sub-200-nm lateral dimension and microstructures in the range of tens of microns were imprinted. However, the nanostructures on the edges of the large, curved substrates were difficult to characterize precisely. Therefore, microstructures were used to measure the structure fidelity and were characterized using profilometry, white light interferometry, and confocal laser scanning microscopy. Regardless of the restricted imaging capabilities at high inclinations for high-resolution nanostructures, the scanning electron microscope (SEM) imaging of the structures on top of the lens substrate and at an inclination of 45° was performed. The micro and nanostructures were successfully imprinted on the edges of the plano-convex lens at angles of 45°, 60°,and 90° from the center of rotation of the rotating NIL tool. The method enables precise imprinting at high inclinations, thereby presenting a different approach to soft UV-NIL on curved surfaces.

A Novel High Concentration Fresnel Lens as a Solar Concentrator

This paper describes the design methodology for a novel Fresnel lens. The original Fresnel lens is obtained from a plano-convex lens, whose spherical surface is split into a number of divisions (called facets), collapsed onto the flat base. Thus, all the facets of the original Fresnel lens have the same radius as that of the plano-convex lens. The proposed design aims to achieve better ray concentration and reduced spherical aberration than the original Fresnel lens by constructing spherical facets with unequal radii. The centers and radii of facets are constrained so that the ray refracted from the bottom vertex of each facet on one side of the optical axis and the ray refracted from the outer vertex of the corresponding facet on the other side of the optical axis must intersect at the focal plane. The proposed lens design has resulted in a 275% gain in the concentration ratio and a 72.5% reduction in the spherical aberration compared to the original lens of the same aperture diameter and number of facets. The performance of both novel and original Fresnel lenses when used as solar concentrators with a conical coil receiver is evaluated. The novel Fresnel lens led to increased heat gain and resulted in a compact solar collector design.