The influence of the secondary mirror position and the lightweight primary mirror on optical performances

2006 ◽  
Author(s):  
S. J. Park ◽  
S. H. Sim ◽  
C. S. Chung ◽  
E. C. Kang ◽  
J. K. Kim
Keyword(s):  
Primary Mirror ◽  
Secondary Mirror

Design and analysis of supporting structure between the primary mirror and the secondary mirror on a space telescope

2015 ◽  
Author(s):  
Chenjie Wang ◽  
Wenyi Chai ◽  
Liangjie Feng ◽  
Wengang Yang ◽  
Wei Wang ◽  
...  
Keyword(s):  
Space Telescope ◽  
Primary Mirror ◽  
Supporting Structure ◽  
Secondary Mirror

scholarly journals Optical Design of a Novel Two-Stage Dish Applied to Thermochemical Water/CO2 Splitting with the Concept of Rotary Secondary Mirror

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3553
Author(s):  
Song Yang ◽  
Jun Wang ◽  
Peter D. Lund
Keyword(s):  
Mathematical Model ◽  
Ray Tracing ◽  
Concentration Ratio ◽  
Thermal Water ◽  
Optical Design ◽  
Two Stage ◽  
Optical Efficiency ◽  
Primary Mirror ◽  
Secondary Mirror ◽  
Ray Tracing Simulation

In this paper, a novel two-stage dish concentrator (TSD) with a rotary secondary mirror (SM) is presented for solar thermal water/CO2 splitting. An in-house code for ray-tracing simulation of the concentrator was developed and validated. Among all feasible geometries, a hyperboloid with an upper sheet is the most popular option and is widely used as a secondary reflector, which is mainly discussed here. All para-hyperboloid geometric combinations can be categorized into three typical patterns (φ1 < π/2, φ1 = π/2, φ1 > π/2, φ1 = field angle of PM). The initial designs of the TSD, respective to different off-axis levels for each combination, were first designed. Then a new mathematical model was introduced to reshape the SM to reach optimal truncated designs. Finally, a new concept of an off-axis primary mirror (PM) combined with the truncated SM was evaluated by using the in-house ray-tracing code. The results include the optical efficiency, concentration ratio and intercepted radiant flux. The best solutions with the highest optical efficiency fall in the range π/2 ≤ φ1 ≤ (π − arcsin 0.8) rads and 0.4 ≤ NA2 ≤ 0.6 (NA2 = sin φ2, φ2 = field angle of SM), which vary with the concentration ratio and inclination angle.

scholarly journals Precision Analysis and Error Compensation of a Telescope Truss Structure Based on Robotics

2020 ◽  
Vol 10 (18) ◽  
pp. 6424
Author(s):  
Rui Wang ◽  
Fuguo Wang ◽  
Yuyan Cao ◽  
Honghao Wang ◽  
Xueqian Sun ◽  
...  
Keyword(s):  
Engineering Application ◽  
High Order ◽  
Wavefront Aberration ◽  
Mirror Surface ◽  
Sensitivity Matrix ◽  
Support Structure ◽  
Inverse Kinematic Problem ◽  
Surface Error ◽  
Primary Mirror ◽  
Secondary Mirror

We propose a new secondary mirror support structure assisted by multi-robotics to improve the observation performance of vehicle-mobile telescope systems. A mathematical model of the displacement at the end of the robotic and the variation of telescope pitch angle is established, then the posture of the robotic is optimized by the Jacobian matrix iteration inverse kinematic problem method. Based on the new support structure, a high-order sensitivity matrix is proposed to establish the mapping relationship between the robotic misalignment and the Zernike coefficient, with the accuracy verified via the Monte Carlo method. The method of adjusting the secondary mirror to compensate the aberration caused by the primary mirror is proposed, and the relationship between the primary mirror surface error and the system error is established under different pitch angles before and after compensation. The experiment and simulation results showed that the adjustment calculated by the high-order sensitivity matrix method can effectively compensate for the misalignment caused by the robotics and the primary mirror surface error to a certain degree. After multiple iterations, the root mean square of the wavefront aberration was better than λ/15. This conclusion provides an engineering application reference value for the secondary mirror support and aberration correction technology of the vehicle telescope system.

scholarly journals Optical telescope with Cassegrain metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3263-3269 ◽  
Author(s):  
Xuan Liu ◽  
Junhong Deng ◽  
King Fai Li ◽  
Mingke Jin ◽  
Yutao Tang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Incident Light ◽  
Astronomical Observation ◽  
Optical Telescope ◽  
Circularly Polarized ◽  
Primary Mirror ◽  
Secondary Mirror ◽  
Infrared Wavelengths ◽  
Cassegrain Telescope ◽  
Imaging Properties

AbstractThe Cassegrain telescope, made of a concave primary mirror and a convex secondary mirror, is widely utilized for modern astronomical observation. However, the existence of curved mirrors inevitably results in bulky configurations. Here, we propose a new design of the miniaturized Cassegrain telescope by replacing the curved mirrors with planar reflective metasurfaces. The focusing and imaging properties of the Cassegrain metasurface telescopes are experimentally verified for circularly polarized incident light at near infrared wavelengths. The concept of the metasurface telescopes can be employed for applications in telescopes working at infrared, Terahertz, and microwave and even radio frequencies.

scholarly journals PbS and CCD Array Autocollimation Micrometers for the Infrared Meridian Circle

1995 ◽  
Vol 167 ◽  
pp. 337-338
Author(s):  
V. N. Yershov
Keyword(s):  
Focal Plane ◽  
Optical Axis ◽  
Meridian Circle ◽  
Pulkovo Observatory ◽  
Primary Mirror ◽  
Small Constant ◽  
Ccd Array ◽  
Secondary Mirror ◽  
Axis Position ◽  
Optical Unit

A new infrared meridian instrument is being developed at Pulkovo Observatory. The main purpose of the instrument is to extend the fundamental coordinate system to the K-infrared waveband and to faint stars at visual and I-wavebands. The instrument has a 30-cm primary mirror made from astrositall. An intermediate focal plane is used to introduce luminous reference marks. One can obtain autocollimated images of the marks at the intermediate focal plane with the use of a polished chamber located around the central hole of the primary mirror. The secondary mirror of the telescope forms images of the marks and of their autocollimated counterparts and passes them to the plane of a photodetector (Fig. 1.). The luminous marks give a reference frame for the measurements. These measurements are not affected by displacements of any optical unit placed after the intermediate focal plane or by displacements of the detector. The measurements are done relative to the coordinates of the average between positions of the luminous mark and its autocollimated image. Any small constant difference between the center of curvature and the optical axis position can be determined in the laboratory.

Structure Design and Finite Element Analysis of Receiving System for Optical Communication

2013 ◽  
Vol 552 ◽  
pp. 548-553
Author(s):  
Shu Bin Liu ◽  
Tian Yuan Gao ◽  
Ya Bo Wu
Keyword(s):  
Optical Communication ◽  
Rapid Development ◽  
Structure Design ◽  
Laser Communication ◽  
Test Results ◽  
Element Analysis ◽  
Primary Mirror ◽  
Secondary Mirror ◽  
Key Technologies ◽  
Mirror Structure

Along with the rapid development of science and technology, and due to the special advantage of laser communication, such as big traffic and good secrecy, the application of optical communication is more and more wide. One of key technologies is the structure design of receiving system. In this paper, a structure of receiving system for optical communication based on Cassegrain system is introduced. Consist of the support structure of primary mirror and secondary mirror, adjustment structure of secondary mirror, structure design of reflectors, etc. FEM is used to analyze the distortion of primary mirror which is based on this structure. The distortion is caused by pressure, self-weight and temperature change, etc. And the stress deformation of primary mirror tube is analysed particularly. Analysis and test results demonstrate that the design project is reasonable.

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