Parabolic reflector

About: Parabolic reflector is a research topic. Over the lifetime, 3375 publications have been published within this topic receiving 30735 citations. The topic is also known as: paraboloid reflector & paraboloidal reflector.

40 W Continuous Wave Ce:Nd:YAG Solar Laser through a Fused Silica Light Guide

Abstract: The solar laser power scaling potential of a side-pumped Ce:Nd:YAG solar laser through a rectangular fused silica light guide was investigated by using a 2 m diameter parabolic concentrator. The laser head was formed by the light guide and a V-shaped pump cavity to efficiently couple and redistribute the concentrated solar radiation from the parabolic mirror to a 4 mm diameter, 35 mm length Ce(0.1 at.%):Nd(1.1 at.%):YAG laser rod. The rectangular light guide ensured a homogeneous distribution of the solar radiation along the laser rod, allowing it to withstand highly concentrated solar energy. With the full collection area of the parabolic mirror, the maximum continuous wave (cw) solar laser power of 40 W was measured. This, to the best of our knowledge, corresponds to the highest cw laser power obtained from a Ce:Nd:YAG medium pumped by solar radiation, representing an enhancement of two times over that of the previous side-pumped Ce:Nd:YAG solar laser and 1.19 times over the highest Cr:Nd:YAG solar laser power with a rectangular light-guide. This research proved that, with an appropriate pumping configuration, the Ce:Nd:YAG medium is very promising for scaling solar laser output power to a higher level.

Optical reflector, illumination optical system, light source system and illumination optical apparatus

Abstract: An optical illumination system according to the present invention is provided with an optical reflector for illuminating a surface to be illuminated in the shape of arc or annulus. A reflective plane of the optical reflector is shaped in a special curved surface. Specifically, an arbitrary parabola with a first axis passing through the vertex and the focus of the parabola is rotated about a second axis passing through a point located on the opposite side of the directrix of the parabola with respect to the focus and being parallel to the directrix. The rotation of the parabola yields a parabolic toric surface. The reflective plane of the optical reflector has the curved surface constituting at least a part of the parabolic toric surface. The reflective plane so shaped reflects a light source image emitted from a light source system to illuminate the surface to be illuminated in the shape of arc or annulus.

Unit for measuring optical properties

Abstract: A unit for measuring optical properties. The unit includes the first through sixth reflecting surfaces, a reflecting surface rotating device and an object moving device. In order to accurately measure transmittance, reflectance and phase change in transmittance or reflection of optical elements, especially transmittance of a thick object, the first through the fourth reflecting surfaces M1-M4 are arranged so that an optical path formed by the reflecting surfaces M1-M4 has a shape like an "N" letter and so that light of incidence L1 has the same optical axis as exit light L2. An optical center O is a point that a line segment that connects a point of incidence A with an exit point D intersects an optical path that connects the reflecting surface M2 with the reflecting surface M3. The reflecting surface M2 is an ellipsoid of revolution having foci of the optical center O and the point of incidence A. The reflecting surface M3 is an ellipsoid of revolution having foci of the optical center and the exit point D. A reflecting surface rotating device rotates M4 at the exit point D in conjunction with the reflecting surface M1 that is rotated at the point of incidence A. The reflecting surface M5 is a parabolic mirror that makes light reflected from the reflecting surface M1 parallel. M6 is a parabolic mirror that converges light reflected from the reflecting surface M5 onto the reflecting mirror M4.

An adjustment method for active reflector of large high-frequency antennas considering gain and boresight

Abstract: The design of the Qitai 110 m Radio Telescope (QTT) with large aperture and very high working frequency (115 GHz) was investigated in Xinjiang, China. The results lead to a main reflector with high surface precision and high pointing precision. In this paper, the properties of active surface adjustment in a deformed parabolic reflector antenna are analyzed. To assure the performance of large reflector antennas such as gain and boresight, which can be obtained by utilizing an electromechanical coupling model, and satisfy them simultaneously, research on active surface adjustment applied to a new parabolic reflector as target surface has been done. Based on the initial position of actuators and the relationship between adjustment points and target points, a novel mathematical model and a program that directly calculates the movements of actuators have been developed for guiding the active surface adjustment of large reflector antennas. This adjustment method is applied to an 8 m reflector antenna, in which we only consider gravity deformation. The results show that this method is more efficient in adjusting the surface and improving the working performance.

High-Order Vortex Beams Generation in the Radio-Frequency Domain

Abstract: A novel technique for generating high-order vortex beams in the radio-frequency domain is reported. Vortex beams with non-null radial index are generated by means of a dielectric mask, mounted upon either a twisted parabolic reflector or a conventional one. The far-field intensity pattern is compared to analytical models and numerical simulations, thus illustrating how diffraction and illumination can affect the generated fields.