Angular aperture

About: Angular aperture is a research topic. Over the lifetime, 1771 publications have been published within this topic receiving 27257 citations.

Laser diode-lens alignment with 0.09 or less numerical aperture

Abstract: A light-emitting module includes a laser diode, a laser diode holder, a lens, and a lens barrel. The laser diode is supported by the laser diode holder, and both the lens 2 and the lens barrel are supported by the lens holder. The laser diode and the lens holder engage with each other to be fixed so that the optical axes of the laser diode and the lens agree with each other. The lens holder has an optical fiber fixed in the emergent direction. The lens holder further has an opening to set the numerical aperture for the lens to the laser diode to 0.09 or less.

Compact wide-angle variable focal length lens system

Abstract: A wide-angle variable focal length lens system comprising a first lens unit which is to be kept stationary for varying a focal length of the variable focal lens system and composed of a single positive lens component, a second lens unit which comprises at least one positive lens component and has a negative refractive power as a whole, a stop, and a third lens unit having a positive refractive power; and configured so as to perform variation of a focal length of the lens system and adjustment of an image location by moving the second lens unit and the third lens unit along an optical axis in directions which are opposite to each other. This variable focal length lens system has a field angle of 64° to 74° at a wide position thereof, a variable focal length ratio of 3 to 3.3 and an F number on the order of 2, and comprises a small number of lens components.

Two-lens type optical lens system for taking image

Abstract: A two-lens type optical lens system for taking image consists two lens elements with refractive power, from the object side: a positive first lens element with a convex object-side surface and a concave image-side surface, both the object-side surface and the image-side surface of the first lens element being aspheric; a positive second lens element with a concave object-side surface and a convex image-side surface, both the object-side surface and the image-side surface of the second lens element being aspheric, and an aperture stop located in front of the first lens element. A focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the optical lens system is f, a radius of curvature of the object-side surface of the second lens element is R3, and they satisfy the relations: f/f1>0.9; (f/f1)>(f/f2)>0.35; and 1/R3<−0.01 mm −1 .

Motor vehicle lighting device with an optical fiber having a coupling lens and a transport and conversion lens

Abstract: A motor vehicle lighting device is proposed, having a light source, and having an optical waveguide, which has a coupling lens, which has at least one reflector, wherein the optical waveguide has first and second planes that are perpendicular to one another, and intersect, and wherein the lines of intersection are each defined by a light beam emitted from the reflector. The device is distinguished in that a transformation by the coupling lens occurs such that an aperture angle of propagation directions of the light beams lying in the second planes is reduced, and the aperture angle of propagation directions lying in the first planes is not altered, or is altered less strongly, and in that the optical waveguide has a transport and transformation lens, wherein the coupling lens and the transport and deflection lens are separate components.

On the optimum form of an aperture for a confinement of the optically excited electric near field.

Abstract: Summary A triangular nanoaperture in an aluminium film was used previously as a probe in a scanning near-field optical microscope to image single fluorescent molecules with an optical resolution down to 30 nm. The high-resolution capability of the triangular aperture probe is because of a highly confined spot of the electric near field which emerges at an edge of the aperture, when the incident light is polarized perpendicular to this edge. Previous numerical calculations of the near-field distribution of a triangular aperture in a planar metal film using the field susceptibility technique yielded a nearly quantitative agreement with the experimental results. Using the same numerical technique we now explored the possibility for a further confinement of the electric near field and an increase in its intensity by modifications of the form of a triangular aperture. By introducing a kink on an edge pointing into the aperture, an arrow-shaped aperture is formed with one convex and three concave metal corners. It turns out that this form leads to a substantial further confinement of the near-field intensity at the convex corner. By extending the wings of this arrow-shaped aperture a further 5-fold increase of the intensity can be obtained without a deterioration of the confined spot.